So I’m not sure about all of you, but I think my main activities outside the house since March have mainly included escaping*1 into nature! Mainly surfing the local beaches in LA, hiking on some local trails, and two multi-day backpacking trips in the Sierras.
Backpacking to Valentine Lake! (Mammoth Lakes Area, Inyo national forest)
Enjoying the scenery near Valentine Lake, Inyo Nat.Forest
Valentine Lake, Inyo National Froest
Yesenia stuck in the tent during the blizzard! Valentine Lake, Inyo National Forest (early June.. bad decision.. no campfires allowed due to COVID19 = BRRRR)
By the Kern River @ Kennedy Meadows- southern Sierras
Kennedy Meadows- southern Sierras
In my hammock overlooking the Bridge @ Kern River, Kennedy Meadows
PCT trail!! this is the beginning part of the sierra leg of the trail!
w/ my guard dog.. lol – Kennedy Meadows- southern Sierras
Since I love these treks so much, I recently took some youth, instructors and parents from a local South LA educational program*2: https://www.theknowledgeshopla.com/programs on a nature hike yesterday. I decided to take them to the Los Leones trail – since its only a 30 min drive, not too strenuous and is a fairly short hike (if your want it to be). The hike is 2.6 miles round trip if you decide that your end game goal is the bench overlooking the Pacific Palisades, Santa Monica and the ocean. You can however go much further!
In addition to cape ivy- another invasive plant that we found and that I hadn’t previously known about was the invasive black mustard plant! (see the yellow flowered plant below)- not only is it destructive to native flora and fauna but it can also serve as kindle for Autumn fires in California- yikes! Read more here
Myself with the participants from the KnowledgeShop in South LA! Note- we all had masks but some folks chose to take them off for the photo -which was pretty low risk all of us had to test negative for COVID19 prior to the trek
Showing everyone how to use iNaturalist (from a distance!)
One of the girls showing me the black woolly bear caterpillar she found!
The invasive Cape Ivy strikes again! (native to South Africa, nicknamed ‘California’s Kudzu’
Gall-forming insects! Basically they take the plant hostage and force the plant to build them homes while they suck all of the nutrients out of it…
Native California Buckwheat- what of the participants thought it looked like popcorn- I agree!
Native Coyote Brush! (Baccharis pilularis)
Cottontail Rabbit (I think) Sylvilagus
California Bordered Plant Bug Largus californicus
Native Lemonade Berry (Rhus integrifolia)
Native Laurel Sumac (Malosma laurina)
Invasive Black Mustard Plant – boooo bad plant! Brassica nigra
Gorgeous view from the Los Leones trail at the bench
Beautiful view on the way down the trail
Beautiful view along the Los Leones trail
Originally one of my aims was to show all of the participants how to use iNaturalist so that they could all try to identify the flora and fauna while on the hike, and after the hike in their own backyards/neighborhoods. They all had downloaded the app onto their phones before coming to the hike- however one short sight I had is that we did not have very good cellular service.. ha (oops!).. So instead I tried to tell them a bit about what I knew (without the help of iNaturalist) and we also took a lot of photos (above) for post-hike identification (Ive tried to identify a lot of these in the captions above!).
I think overall everyone had a lot of fun. After the group nature hike, I ended up taking the trail for a couple miles further to enhance the workout factor!
*Footnotes! (or how about some Footloose?!) Dang I just gave away my age….
*I will admit that I should not be using the word ‘escape’- see this great essay by William Cronon -since nature is technically all around us all of the time.. take that fly that is on your windowsill or maybe even on your arm right now! I think in this sense that we should all appreciate both proximate and distant nature, and take extra care of our immediate surrounding nature-so that we never feel like we need to escape to wilderness.
TheKnowledgeShop works in conjunction with Stem54.. and these two educational youth programs and their leaders- including Yolande Beckles and Dr. Michael Batie are truly making an amazing difference in the South LA community and Beyond! Check them out!
Wow has 2020 been an insane year globally and in the USA..
But has it? In my opinion things have always been insanely messed up in this country and finally now the majority of Americans paying attention and trying to do something about it.
We have seen protests all over the country and world, which is a promising sign. However, we have also seen anti-protestors, white supremacists and fascists trying to stop these protests and trying to cause harm to the protestors and African Americans.
In fact, my cousin-in-law Daniel Gregory, whom is African American, was recently shot while trying to stop an anti-protestor that had driven his car through a crowd of protestors in Seattle, WA on June 7th, 2020. You can read the article here. I am relieved Dan is in stable condition now, but he is ridden with medical expenses, so please donate to the gofundme page hereif you are reading this and want to help Dan the Hero (or you can bypass the fees and send Dan funds directly through cashapp: $Dthunderg).
“A man drives toward the crowd at 11th and Pine, injuring at least one person, before exiting the car and brandishing a firearm”. Image: Dean Rutz / The Seattle Times Daniel Gregory (my cousin in-law) is pictured here reaching into the car to try to stop the driver (he was soon after shot by the driver, and now is in stable condition at a hospital). Please donate to him to help him cover his medical expenses via gofundme.
Perhaps protests like these, and those all around the world, as well as long overdue-attention have finally arrived due to the imperfect storm of COVID, Environmental injustice and civil injustice including the recent murders of Ahmaud Arbery, Atatiana Jefferson, George Floyd, Breonna Taylor and many other African Americans in the image below.
I’m not African-American, so Im not going to act like I know everything, or try to tell their narratives. I also have not gone into sufficient detail describing the atrocities against people of color in this nation or the concept of structural racism. Instead I’ll link to resources below this post that have been distributed from graduate students in the Earth and Sciences Department and have been circulating around at USC. Many of the resources (listed and linked below this blog) have been produced by African Americans, the very voices that deserve to be heard louder than any white narrative.
However, one subject that I am more knowledgeable in that relates intensely to the Black Lives Matter Movement is the intersections between Environmental Health and Social Justice – aka Environmental Justice.
To clarify Environmental Justice, let’s use the definition from the EPA:
“Environmental justice is the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. This goal will be achieved when everyone enjoys: the same degree of protection from environmental and health hazards, and equal access to the decision-making process to have a healthy environment in which to live, learn, and work”.
To explore how communities of color are exposed to more pollution and hazardous waste- check out this environmental justice mapping tool, and enter in your address to see what types of pollution or environmental hazards are near you. https://www.epa.gov/ejscreen
If you live in a wealthier area, go ahead and enter in an area where you know more low-income people or people of color live.. I guarantee you that you will be shocked (or maybe not if you are already well-informed) to find out that not only are people of color more likely to be discriminated against in their day to day lives. .but they are also living in hazardous areas that are affecting their health!!! I think this outrageous, and we need to do more about this issue in our country, and around the world (Not to mention how we ship a lot of our hazardous e-waste to countries in Africa.. leading to environmental injustice from global change).
Go ahead, and explore this for yourself, by using the COVID mapper: https://covid19.jvion.com/#! and then again go back to the environmental justice map I showcased previously: https://ejscreen.epa.gov/mapper/ and you will see for yourself how environmental health and social justice intersect (again this is called Environmental Justice).
I will stop here, because this has already become very long, but Environmental Justice extends way beyond what I have covered here. To learn more: check out a free youtube lecture by another professor, Chelsie Romulo (University of Northern Colorado) on environmental justice, https://youtu.be/swHXOOiJQys.
Below, I have also included list of what you can do to become more educated about anti-racism and being a better ally to the black community. Because remember Environmental Health and Social Justice are linked, and you need to be informed about both to make a difference! You can do it.. now go out there and be the bad ass activist that you are!
Daily Learning:
Justice in June – a syllabus for folks new to anti-racism (or wanting to learn more) to spend some time each day in June learning how to be a better ally to the black community (this contains several of the resources listed below)
(you can get around this paywall with your library proxy if you are part of a University)
If Not Now, When? The Promise of STEM Intersectionality in the Twenty-First Century, by Drs. Kelly Mack, Orlando Taylor, Nancy Cantor, and Patrice McDermott
Wow.. has life taken a surprising turn.. not just for me but for the whole world. With the onset and spread of the COVID19 pandemic we have seen people across the whole world have to adjust and make changes in both their personal and work lives. It’s been interesting for myself and other teachers (K-12 and Higher Education) to try to quickly readjust and attempt to deliver a premium education for our students. Its also been comforting to see the rebirth of ‘community’ such as folks helping out their elderly neighbors and teachers banding together and sharing online teaching resource and tips.
Thus the focus of this post is to share what others have shared with me, as well as some of my lessons I have learned in the first week of online teaching.
However before I go into the meat of online teaching.. let me back up a bit to BC (Before Coronavirus) time period. As you may know – I recently started a teaching postdoc position at the University of Southern California (USC) , which has been absolutely amazing so far. In the Fall semester I taught an upper division Ecology class and a lower division Env. Studies GE course, and now in the Spring Ive been teaching two sections of the lower division Env. Studies GE course (no labs this semester thank goodness!)
It all seems like a blur but just two weeks ago USC was still proceeding business as usual… as were most schools in California. Then as we got closer to our Spring Break, USC announced a ‘trial-period’ of online teaching for 3 days before Spring Break so that we can adjust our methods as needed “IF” we needed to extend to online teaching. Then as the # of COVID19 cases rose (see here a live tracking website made by 17 year-Avi Schiffmann)- USC quickly changed the plan to teach remotely after Spring Break until April 16th… and then two days later extended online teaching to the end of the semester. Ha.. people’s plans have been changing so fast.. but not as fast as the virus spreads and mutates: https://nextstrain.org/ncov
Immediately I had mixed feelings about online teaching for the rest of the semester: Cons: Im not very good at this online teaching thing yet and now I better get good at it fast! Pros: I can teach in my workout clothes (with makeup on and a nice top) and foster or adopt a dog since Ill be home all day! (..already made progress on latter- see my foster-fail/adopted dog- Yesenia) from the North Los Angeles Animal Shelter. I still have to officially fill out her adoption paper work.. but haven’t been able to go to shelter yet due to COVID19 restrictions.
Yesenia loves playing ball
and loves hikes!
Anyhow, now that I have my trusty dog by my side, I have been focusing on how to improve my online classes. I also have received lots of helpful links that I am pasting below this blog post to pass on the shared resources and knowledge.
At USC most of the teachers and myself have started using Zoom as well as Blackboard, the latter which most of us have regularly used to post announcements and assignment instructions, as well as a platform for students to turn in assignments which we can grade online. So far: I have definitely learned some dos and don’ts with Zoom and remote teaching and testing:
ZOOM Dos:
DO RUN A PRACTICE SESSION FIRST! I suggest practicing with your actual students in the physical classroom if possible prior to going to online only (this is what I did and we sorted out some issues on the student’s side of things this way, as well as how to share the powerpoints for them in slide show not presenter mode), but if not possible – get together w/ some colleagues and practice with each other (my mom actually did the latter and I thought that was a great idea!)
Do set the settings to put everyone on Mute when they enter the room
Do tell the students to unmute themselves when they have questions and feel free to speak whenever (much more engaging and feels more like a real class than written chat-room based questions/comments)
Do TURN YOUR VIDEO ON and encourage students to turn their videos on if they feel comfortable-I noticed it makes me feel like Im actually talking to someone than just a green light on my laptop
Do use the ‘polls‘ in lectures to mix things up and encourage participation
Do record your lectures in the cloud in case you have international students that are in different time zones.
ZOOM Don’ts:
Don’t just lecture at the students and forget about encouraging participation and interaction (I actually am still working on this one.. it is more difficult than in-person classes because you can’t see all your students…)
Don’t assume that all of your students are on the same time zone. I know for me it took me a couple days to realize some of my international students had gone back home. Thus I needed to adjust my expectations for them and let them watch recorded lectures and makeup any in-class activities w/in 24 hours .
Don’t talk too fast (oops.. Im also working on this one…).
Blackboard tips and protocols for online testing: So I actually had in-class midterms planned for this week (BC) and I had to adjust to remote testing formats. I knew I didn’t want to use the ‘honor system’ since some students might cheat and that wouldn’t be fair to others… so I decided just to make it completely open-note, but I expanded on the # of questions in the exam so that it is fast paced enough that the students won’t have time to look up every question. Thus they still have to prepare for the exam a decent amount. I also decided to go with the “Respondus Lock Down Browser” app available in Blackboard for Online Exams. It basically locks out everything on a student’s computer except for the exam. For me the only reason why I decided to go this route is so that students can’t copy and paste answers from their lectures or from internet sources. But I did tell them they could use their ipad or iphones or other computers and notes for information. The key with online testing, just like with online classes, is to have the students PRACTICE! I offered my students 2 pts extra credit to try a practice exam with sample questions and the lock-down browser so that we could get all the kinks out of the way ahead of time.
I also told me students to have a plan for what computers and internet sources they were going to use, and a backup plan in case they had an internet or computer malfunction. As for the actual testing day/time I will be online and can answer questions my students have via email in live-time.
For my international students and DSP students, blackboard testing tools lets you make make exceptions and adjustments to the test time period, date and time of test on a person-by-person basis. So for my students in countries with very different time zones, I adjusted the time of the exam to be at a more reasonable time for them. For my DSP students, I was able to provide them with extra time to take the exam.
As far as how to make exam questions- I used the Blackboard ‘question pools” and then used questions from those pools to make the exams. The students are not able to see the question pools or the tests until the available date/time that you dictate in the settings. The tests are this week.. so fingers crossed they go smoothly. If not then Ill have to adjust and just make a take-home essay-based assignment for the final exam. The key about teaching and adjusting to a global pandemic is to be flexible, adapt and stay healthy. To stay healthy, again I totally recommend fostering or adopting a pet, as well as getting more into cooking and working out everyday. (Lots of great online videos to stay in shape while sheltering-in-place, such as this oldie but goodie with Billy Blanks!: https://www.youtube.com/watch?v=jOaartzSX6A)
With this said, Im leaving you with some great resources that have been forwarded to me from many great teachers: You got this!
Last Thursday on a typical sunny Californian day, I met up w/ researchers, Kirsten Sheehy (UCSB RIVRLAB), Bill Neill (Riparian Repairs) and Noa Rishe (California Department of Parks and Recreation) to romp around Topanga State Park in search of the invasive Cape ivy, Delairea odorata. As soon as we stepped foot onto the Los Leones trailhead we could see the vast entwined vines of this relentless invasive ivy climbing over and smothering all of the native species in its path, hence its nickname- the ‘California kudzu’.
Me, standing in a thick blanket of Cape ivy near Los Leones trail in Topanga State Park
Kirsten Sheehy, Research technician at the UCSB RIVRLAB inspecting the best place for the first release of the biocontrol agents- the gall-forming flies
Native to South Africa, Cape ivy was originally introduced into the USA in the 1850s for ornamental purposes due to its pretty green color with lush yellow flowers. However, looks can be deceiving as in some areas this invasive weed has reduced native plant species richness by 36%, and decreased native seedling abundance by 88% (see Alvarez and Cushman 2002). In addition to its detrimental impacts on native plants, this invasive weed also produces many chemical defense compounds (eg. pyrrolizidine alkaloids and xanthones), which make it toxic and unsuitable for foraging by resident mammals; and potentially detrimental to fish survival if substantial amounts of these chemical compounds end up in waterways. Aside from its toxins, this weed can interfere with nesting sites by many riparian-dependent birds. This invasive weed is also quite the ecosystem engineer due to its shallow root system contributing to serious soil erosion problems on hillsides; as well as potentially forming a serious fire hazard due to its dried out foliage hanging over native trees during the dry season.
Thus, there is a dire need to control the spread and growth of this menacing invasive vine. Invasive weeds can be controlled in several manners including herbicide chemicals, mechanical removal (via hand-labor or machines), and biological control. In classical biological control, a pest or weed’s natural enemies (for example, the insect herbivores of Cape ivy) are collected from its geographic place of origin, tested for target specificity and efficacy, and then released into the invaded region.
Successful biocontrol agents can reduce pest populations below threshold levels that cause problems for humans and native species. Once established, biocontrol agents can provide a sustainable, long-lasting management option as biocontrol agents are self-reproducing and self-distributing. Biocontrol agents will not eradicate every target pest or weed individual but this is actually a positive feature as it prevents population crashes of the biological agent and promotes the long term control of the weed. In sensitive or protected regions, biological control and hand-removal of invasive weeds are often the preferred method of control in order to reduce any negative impacts to the surrounding native ecological community.
Kirsten Sheehy holding up a vial of the biocontrol agents, the gall-forming fly: Parafreutreta regalis
Hence, last Thursday was quite a monumental day as it marked the first release of the biological control agent for the control of the invasive cape ivy in the greater Los Angeles Region. The biological control agent in this case is the gall-forming fly, Parafreutreta regalis Munro (Diptera: Tephritidae), that has already been approved for release after undergoing intensive testing through the USDA-ARS to ensure that it only targets the invasive cape ivy, in order to prevent any non-target effects on local plants. Similar to its host plant, this gall-forming fly is native to the Cape Province of South Africa and is known to stunt the growth of Cape ivy in both the laboratory and in the field. Thus, it is expected that this biocontrol agent will reduce cape ivy’s ability to spread and climb, both which would reduce the smothering impacts of this invasive weed on native vegetation.
Kirsten Sheehy releasing the super-hero gall-forming flies (Parafreutreta regalis) into a cage for biological control of the invasive Cape ivy
In two weeks from now Kirsten Sheehy and the UCSB RIVRLAB will come back to make sure that the galls are forming on the ivy before removing the cage. Once the galls have formed, these flies are pretty much on their own, continuing the cycle of injecting their eggs into new unsuspecting cape ivy hosts, and forming new galls that promote generation after generation of weed-controlling superheroes. Of course Kirsten will continue to make periodic new releases of adult flies in the SoCal region to increase the genetic variation of this fly to ensure the success of these new populations in the Los Angeles Region. The goals are to establish these super-hero flies in at least one site per coastal county in California to serve as ‘nursery’ sites for future regional releases. San Diego Co. is next up on this lucky-list of biocontrol study sites.
In addition to this beneficial fly, further biological control research on a stem- boring moth, Digitivalva delaireae Gaedike & Krüger (Lepidoptera: Acrolepiidae), is underway via the USDA-ARS (see Mehelis et al. 2015) and is likely to be approved for release in the near future. This stem-boring moth is actually expected to have an even greater impact on controlling Cape ivy, especially if it is combined with the impacts of the gall-forming fly. Once approved, we hope to add this additional superhero biocontrol agent in the SoCal Region in order to reduce the ecological crimes of the invasive Cape ivy villain. Stay tuned for the sequel.
In the mean time, if you would like to learn more, see the contact information, links and research articles below.
Mehelis, C.N., Balciunas, J., Reddy, A.M., Van Der Westhuizen, L., Neser, S., Moran, P.J. 2015. Biology and host range of Digitivalva delaireae (Lepidoptera: Glyphipterigidae), a candidate agent for biological control of Cape-ivy (Delairea odorata) in California and Oregon. Environmental Entomology. 44(2):260-276. doi: 10.1093/ee/nvu030.
Acknowledgements:Additional thanks to Dr. Tom Dudley and Dr. Adam Lambert from the UCSB RIVRLAB and Danielle LeFer from California Department of Parks and Recreation for coordinating this momentous day, and to Dr. Patrick Moran, Dr. Scott Portman, Dr. Angelica Reddy, Dr. Chris Mehelis and additional researchers from USDA-ARS in Albany, CA for all of the rigorous testing of this weed and its biological control agents.
So, I have some exciting changes and news! Starting Monday I will be teaching two undergraduate classes at USC this Fall! I recently changed positions at USC as a postdoctoral researcher (studying parasite-host interactions in the marine phytoplankton community) to a new postdoctoral teaching fellow position. As much as I love research, I really missed teaching and mentoring and wanted to dive deep into teaching to gain more experience as an instructor of record.
I will be teaching an upper division Ecology course with a lab (BISC 315), and a lower division Environmental Studies course (ENST100). I’ll also be participating in USC’s CET New Faculty Institute , a faculty development program. I’m super stoked, and have been hustling for the past month to modify and design the curriculum and get all of the materials ready for the Ecology lab course. I thought most of my time would be modifying and designing new lectures and labs…. and I’ve definitely had some surprises along the way regarding where all of my time goes:
It takes a lot of time to prep a lab room/facility if by chance you are ‘lucky’ enough to have a lab that does’t have a lab manager…. The benefits are that I don’t need to share the lab w/ too many other classes.. so I can leave things set up from time to time. Plus my TA can use the lab as her office hours! Cons- it is up to me to fix everything and get everything ready for the semester! So I definitely spent some time on tasks like getting rid of that old whiteboard that doesn’t erase anymore and fixing the new one that somehow arrived broken (thanks to the hubby for the latter!). On the same note- all of that old hazardous waste in the fume hood.. yup- need to condense it and call EH&S to whisk it away. ….Those old dead snails that have been rotting in the back of the room for over 6 months.. .yea I put those in the dumpster. That cart with some strange devices that look like broken microscopes.. turns out nobody knows who it belongs to.. but it can’t be thrown away. I think that one will just get put in storage…. Oh and then the broken Monitor that we need to use for presentations…thank goodness for IT support…
Then there is the ordering and organizing of all of the supplies for each lab. Which means you have to modify or design labs and fully prep all of the lab instructions and hand outs before the semester starts (which is a good thing anyhow). I did this… and I even made sure we had phase-contrast microscopes before I designed a lab. However I learned a big lesson- always physically check out the equipment before you spend all of the time designing a lab and handouts! Turns out – the phase-contrast microscopes that we have available for our teaching labs don’t have 20X objectives. Later I learned it is standard for most microscopes to only have 4X 10X 40X and 100X.. and I guess 20X is rare.. who knew!?! Unfortunately, one of the labs I spent a couple days designing (including all the handouts, instructions and reading materials)- requires 20X objectives lens… oops! So had to scrap that one and cut my losses. In the end it worked out and I extended a lab on insect diversity instead which I think will be better anyhow. On this note- I am super grateful to the Entomology Curator, Brian Brown, at the Natural History Museum for donating some of their no-data insects for my class insect collection. Im planning on putting them on a backdrop of the phylogeny and evolution of insects (Misof et al. 2014, Science) so students can see the different adaptations that have evolved through time in the Class Insecta.
In a couple weeks I will mount these onto a phylogeny backdrop w/ an evolutionary timescale.. new photos to come later. Insects courtesy of the Natural History Museum’s Entomology Collection in Los Angeles.
Lastly there are the little things- like moving into a new office and setting up the space so that it is beneficial for office hours; learning how to use the departmental printer/copier; going to all of the classrooms and making sure my computer connects properly (and organizing those chairs in the classroom since it looks like a rave recently happened!); and meeting with teachers and TAs that taught the classes in previous years so that I can get the run-down on what worked and what didn’t work.
testing the room out!
Everything works! Yay!
Getting the office space ready
Printing the syllabi out for the smaller class!
Then when I do actually have time to work on my lectures.. I find myself going down rabbit holes of finding cool documentaries for my Environmental Studies lectures, such as my new one on the interactions of society, culture and the environment- (Check out this cool documentary series on Native Americans and their stewardship of the land and waters); or going through all of the scientific literature on interesting topics that I am incorporating into my lectures such as sex-changing fish for my ecology lecture on mating behavior and sexual selection (which by the way is how I got interested in ecology in the first place over 20 years ago!.. oh geez Im getting old!)
Figure 1: Todd et al. 2017. Female Mimicry by Sneaker Males Has a Transcriptomic Signature in Both the Brain and the Gonad in a Sex-Changing Fish. Mol. Biol. Evol. doi:10.1093/molbev/msx293
Anyhow… Monday is right around the corner.. so with that Im going to start uploading everything onto our online BlackBoard system… here we go!
Ps- if any of my students are reading this— don’t worry- I got this! You are in good hands… ha ha ha.
One of the reasons I haven’t posted for a bit besides the normal-busy routine is that it is Spring Time! What’s that got to do with anything you ask?
BLOOMS! BLOOMS OF EVERYTHING!
Me in the Anza-Borrego Desert in California, next to a flowering Ocotillo plant
Besides blooms of flowers in the desert (such as those in the Anza-Borrego Desert), we also get blooms of phytoplankton along the coast in Southern California.
Here, in the spring we get very high winds that can result in upwelling events in the coastal ocean, pushing waters offshore and bringing up cold, nutrient rich water from the bottom ocean layers to the top layers.
This increase in nutrients (such as nitrogen, phosphorous, iron, etc.) can result in massive ‘blooms’ or increases in specific phytoplankton species (diatoms, dinoflagellates, etc.), since typically their densities are limited by nutrient availability. During these blooms, whoever wins the space and resource competition will dominate… until they get run down by grazers, parasites or viruses.. or run out of their limiting nutrient. Once these species decline this then provides space/resources for the next dominating species.
of Upwelling (Image from Sanctuary Quest 2002, NOAA/OER)
These upwelling events also offer AWESOME opportunities for scientists to examine the species dynamics, and the mechanisms that result in some species or functional groups of phytoplankton to dominate over others.
This year, our laboratory (the Caron Laboratory at USC) decided to start our sampling period after we noticed strong winds on April 9th.. and I mean Strong! I was biking to my circus class that evening, and a branch literally flew and hit me.. luckily I was wearing a helmet 🙂 During lab meeting that week, we were all telling each other the horror stories of the strong wind, and realized.. ‘woah!’… we should start our spring sampling asap! So we quickly contacted the amazing Santa Monica Pier Aquarium (Heal The Bay) and received permission to use some of the space there to do our sample processing for three weeks. Then we finalized our schedules, rotating each daily to sample and process the water off of the Santa Monica Pier. Each day at 8:30am, we get to the aquarium, load up our cart with the RBR (an oceanographic instrument that measures temperature, salinity, chlorophyll and dissolved oxygen), a bucket and container for loading up sea water, and a 20 micron plankton net to collect a concentrated water sample. Then by 9am, we are loading up water into our collection container, and then rolling the water back to the aquarium to filter some of it down as fast as possible onto filters that we flash freeze for DNA/RNA extractions. We also preserve some of the whole sea water for relative abundance counts of the different organisms via microscopy, and we sample the water for extraction of chlorophyll and domoic acid (toxin produced by some diatoms). Once we get back to the lab, we inspect the concentrated samples from the plankton net to get a quick overview of who is in the water, and who is the dominating species.
Me on the Santa Monica Pier sampling water
Look how brown the filter is! So much biomass from all the phytoplankton!
Our filter rig to filter the water from the pier
Our set up in the back of the aquarium
This year the sampling has been super interesting! It started off with a diatom and dinoflagellate bloom, and it looks like the diatoms have been CRUSHED by a parasitoid, Cryothecomonas spp.! Once the diatoms crashed, the dinoflagellates increased more, in particular two species are currently dominating: Akashiwo sanguinea and Cochlodinium spp. (species will be determined after we get our molecular sequences back). I also found some tintinnid ciliates parasitized by Eudoboscquella parasitoids.. so beautiful.
Guinardia sp. with Cryothecomonas sp. parasitoid
Dead Guinardia sp with Cryothecomonas sp. parasitoids
Tintinnid (Eutintinnus sp.) with parasitoids (Euduboscquella sp.)
Cochlodinium sp. (dinoflagellate)
Akashiwo sanguinea (Dinoflagellate photo by Jennifer Beatty)
In addition to using molecular sequences for identification of the different taxa, our laboratory also analyzes the RNA sequences (using bioinformatics) to examine gene expression of the different taxa that are increasing and decreasing during the bloom. These methods can help us determine when species are taking up specific nutrients, when they are multiplying, when they are stressed, and even if they are being attacked by parasites. Lastly, my work in particular during this spring bloom will examine the dynamics of these species and their parasites through time using qPCR (quantifies the relative number of the hosts and parasites by comparing samples to standard curves).
We have five more days left of daily sampling, and I will be sure to follow up with another blog on the results of this spring bloom sampling period. I will also post soon about the exciting results from a massive laboratory experiment that I just finished. Stay tuned!
Some of the students and myself and the IEA LABs parasitology workshop that I gave this Saturday. I think all of us were super excited to detach the parasitic female and male isopods from the host mud shrimp!
My main learning objectives for the students in the workshop were to: 1) Define different types of ecological relationships, including the different types of symbiotic relationships; 2) differentiate among parasites, parasitoids and pathogens; 3) get acquainted with different parasite lifestyles- including direct transmission, vectored transmission, trophic transmission, parasitic castrators, host behavior modification, etc. 4) revel in the sheer shock and aw of diverse parasites; 5) become familiar with using microscopes; and 6) gain experience with some basic dissection techniques.
I found some super awesome and educational parasite videos during the process of getting my interactive lecture together-including videos of:
This was also a great opportunity to become more acquainted with local parasitologists and the common parasites and hosts in the Los Angeles area. This meant connecting with my local parasitologist colleagues (many of whom are part of the Southern California Society of Parasitologists) and finding some parasite ‘hot-spots’ so that I could bring in ample numbers of snails, crabs, shrimp and protozoans for some hands-on activities including dissections and mounting slides on the microscope.
Below was one of the students’ favorites – the parasitic isopod couple (yes.. male and female showing their love for each other all while parasitizing the host shrimp). ‘Couples that parasitize hosts together.. stay together!.. awww’
Photo: 2017 @HakaiInstitute Bioblitz Team
Ectoparasite demonstration at my workshop for IEA-LABs on Feb.16.19
They were also amazed by the marine protistan parasitoid Parvilucifera sinerae, that they happened to catch in the act of bursting out of its dinoflagellate host (and thus killing its host!). I am particularly fond of this parasitoid right now.. since I’m working with marine plankton communities every day at USC. You can read about some of my current postdoc work here
The dinoflagellate, Lingulodinium polyedra, parasitized by the perkinsid parasitoid, Parvilucifera sinerae
This event reminded me that one of the main reasons why I love science is actually the amazing support from other scientists.. and getting to know these scientists as people! For instance, I could not have done this workshop, without the support of Dr. Kevin Lafferty (USGS, UCSB) and Dr. Ryan Hechinger (Scripps-UCSD) who provided me with some hot spot localities for collecting highly-parasitized populations of the California Horn Snail, and how to access those hot-spots. These snails are parasitized by many different species of trematodes (Platyhelminthes), which are trophically transmitted parasites. This means that these parasites use multiple hosts to complete their life cycle and thus require their first set of hosts to be eaten by their final ‘definitive’ host. These parasites are also great for show-and-tell purposes since the cercariae (parasitic stage that searches for the next host) are larger than 100 um, move around quite a bit and can often have charismatic features, such as eye-spots.
Typical lifecycle of parasitic trematodes that use the California Horn Snail as their first intermediate host. Figure from: Torchin et al. 2005, Biological Invasions “Differential parasitism of native and introduced snails: replacement”of a parasite fauna
I also got more great advice from Dr. Kimo Morris, a Professor at Santa Ana Community College and Dr. Ralph Appy regarding what other critters I could collect, and how to alter my workshop and lectures to appropriately target middle schoolers. Dr. Ralph Appy actually invited me to his laboratory to learn how he digests crabs and shrimps with an acidic solution to fool the parasites (in these hosts) into thinking that they are in the stomach of the next host of their life-cycle.. with the ultimate goal of collecting the parasites into a pool of liquid for research or show-and-tell. Dr. Ralph Appy provided me with a ton of ghost shrimp, mole crabs (sand-crabs) and the really cool mud shrimp that was parasitized by two ectoparasitic isopods (one female and one male).
All in all… I definitely learned a ton from this great opportunity.. and look forward to giving another parasitology workshop to K-12 students in the future (next time with fresher snails.. so they don’t smell so bad!).
This study was a product of my Delta Science Postdoctoral Fellowship to investigate the mechanisms for effective biological control of the invasive water hyacinth in the Sacramento-San Joaquin River Delta (hereafter “Delta”).
In a nutshell: Two weevils (insects) are currently used all over the world for the biological control of the invasive water hyacinth, including the Sacramento-San Joaquin River Delta, California. They have had variable success, with notable reduction of biomass and cover of this invasive aquatic weed in warmer climates compared to more temperate climates such as the Delta. Although temperature plays a large role in their success, I also investigated the role of genetic variation in the success of these weevils and whether there is lower genetic diversity and heterozygosity in the Delta compared to the native origin of these weevils (South America). To do this, I used polymorphic microsatellite markers (repeating regions of DNA in the genetic blueprints of a species) to detect differences between individuals and between populations. Additionally, as myself and others noticed weevils from the field that appeared to be hybrids of these two species, I examined whether these hybrid-like weevils are genetic hybrids (meaning that they have genetic patterns representative of the genetic blueprints from both species).
In my opinion, the most important findings from this study were:
We found hybrids! This is huge! These two weevils are introduced all over the world for the control of invasive water hyacinth. So now that we know hybridization occurs, it is critical since to understand how hybridization affects their success. For instance, sometimes hybrids can outperform non-hybrids (hybrid-vigor) whereas other times hybridization can decrease performance, as well as population growth (hybrid-breakdown). I am very excited however that Dr. Julie Coetzee’s laboratory in South Africa is now starting to look into the effects of hybridization between these two weevil species.. so stay tuned (I know I will!) .
Typical elytra markings characteristic of (a) Neochetina bruchi and (b) N. eichhorniae; compared to atypical elytra markings for (c) N. bruchi and (d) N. eichhorniae. Microsatellite markers confirmed that specimens (c & d) are hybrids. A weevil (c) from the study site in California resulted in 100% amplification of markers for N. bruchi and 80% amplification of the markers for N. eichhorniae, whereas a weevil from Texas (d) resulted in amplification of 25% of the markers for N. bruchi and 100% of the markers for N. eichhorniae.
We found that low genetic variation from demographic bottlenecks (small populations of the weevils being introduced over and over again through the biological control programs), can sometimes be buffered by genetic admixture from multiple introductions. This was one of several findings from this study that was made possible through the unique combination of documented historical records from biological control programs and population genetic analyses, such as those we made with the program, FLOCK.
Partial importation history (a, b) compared to the introduction processes predicted by FLOCK genetic analyses (c, d) of Neochetina bruchi and Neochetina eichhorniae, two weevils native to South America. Arrows depict the direction of the biological control releases and the date initially released, but do not point to the exact release site in that locality. Black lines and yellow‐filled regions represent the routes of importation history that were tested with microsatellite markers.Abbreviations are detailed in Table 1 (Hopper et al. 2019, Evolutionary Applications). Numbers next to abbreviations indicate the number of genetic sub‐clusters found from FLOCK analyses (c, d)
I also think that the lessons I learned from the process of writing this manuscript were very important, and I detail these below.
Lesson 1: Know when to ask for help
This study culminated out of work that I did at UC Davis, advised by Dr. Ted Grosholz, and in collaboration with researchers, Dr. Paul Pratt and Dr. Kent McCue (USDA/ARS), Dr. Ruth Hufbauer (Colorado State University) and Dr. Pierre Duchesne (Université Laval, Quebec, Canada). The latter two coauthors of whom I actually contacted out of the blue during the analysis and writing portion of the study, since I felt like I needed more guidance from experts in the population genetics and data analysis field. I think knowing when to ask for help is really critical in science (no matter what your academic standing is), and it almost always improves the study to get additional opinions and critique. Think of it as a preliminary peer review before the ultimate peer review!
I also asked several folks that are experts in population genetics for advice on the collection, processing and analysis of the data before and during the start of this project, including: Dr. Jeremy Andersen (UC Berkeley), and Dr. Rick Grosberg and Brenda Cameron (UC Davis) and Dr. Neil Tsutsui (UC Berkeley).
Lesson 2: Be Flexible, and Adapt to let the Data tell the Story
The title of this manuscript felt very suitable to me as ecological data are not always clear-cut, and sometimes it can take some time to wade through the weeds of data and figure out how to tell the accompanying story. This is especially true for when resulting data don’t match up with your original expectations and initial story you thought you would tell. The key to this issue, is don’t try to force your old story on the data… get a second opinion if needed, and be open-minded by letting the data ‘speak’ for itself.
Lesson 3: Work Hard, Be Patient and Persistent
I think with anything that you do, sometimes a final product comes easy… and other times it seems like a long drawn out process. This project fell in the latter category, as it was my first time learning about and implementing a population genetics study, and I was working on the analysis and write-up of this study all while starting a new postdoc in an entirely new study system. I think an important aspect to finishing this project was really persistence. I spent week nights and weekends working diligently on the data analysis and writing and re-writing the paper. I also had to be patient with myself as I had to give myself time to learn the new types of analyses (which means new R packages and code!) and time to read all of the important papers in the study field.
If by chance you are also just starting a population genetic study, and feel a bit lost, please see my three-part tutorial blog posts which hopefully will provide some assistance:
Lesson 4: Implement Self-Deadlines and Advertise them to your CoAuthors
Sometimes its hard to finish something if you don’t have a deadline. So make yourself a deadline, and tell everyone about this deadline, so that you are held accountable for this timeline. I actually had some coauthors that needed me to submit this article to the journal by October 1st in order to meet some of their workplace requirements for publications. Needless to say, I pulled an all-nighter and got it in to the journal by 5am that day.. true story….
Nothing like a little pressure to light up that writing-fire…
Lesson 5: Don’t cut corners
This goes with Lesson 3, on being patient. Towards the end of writing up a big study, you might find yourself just wanting it to be over. You would do anything to not have to think about that project or the data anymore. However, crossing that finish line is actually one of the most crucial components and can make or break your ability to get into a decent journal. Having co-authors often really helps solve this problem, as they will call you out on any cut corners (if they are doing their job), and will suggest critical improvements to the paper that maybe you were thinking about.. but were just initially too lazy to do. Also on this note.. Read the proof-version (final version before being published) of the paper word for word! You don’t want any typos in your finished product.. especially true in your Title, Abstract and Figure Legends!
Lesson 6: Celebrate at Each Stage of Completion
Be sure to acknowledge your accomplishments after you submit the manuscript the first time, after the revisions and acceptance, and after the manuscript goes In Press. After all- you worked hard to get to each of those stages, and celebration will help motivate you for the next time you have to do it all over again!
So some good news!- My population genetics study on the two herbivorous biological control agents of water hyacinth: Neochetina bruchi and N. eichhorniae, was finally accepted for publication w/ minor revisions in Evolutionary Applications. I will certainly post it once it is In Press! This was one of the projects I did for my Delta Science Postdoctoral Fellowship research
Part III (right here!) is my attempt to guide you through the jungle of population genetic analyses. I will discuss the main programs and analyses I used and how to properly format your data to make these packages and programs work!
STRUCTURE analysis of N. bruchi across eight populations and eight loci
I am not going to go into nitty-gritty detail because the tutorial for the ‘poppr’ package in R, does a FANTASTIC job on guiding newbies (including my former self) through the process of how to import data into R, exploring the data, and then how to conduct some basic and advanced analyses. The link is here http://grunwaldlab.github.io/Population_Genetics_in_R/index.html
Honestly- this is how I started learning how to conduct population genetic analyses in R.. I kid you not. I literally followed the above tutorial step by step and did almost all of the analyses just to get a feel for the data and how to run population genetic stats.
So- Where to start you ask?
Well, one of my collaborator/coauthors (Dr. Ruth Hufbauer-CSU) emphasized that before you analyze the data, a good first step is to know what your question is, and why you are asking those questions. Then you should base your analyses on those questions.
Here are some example questions:
Where did these samples/individuals originate from?
How many populations are there?
What is the genetic diversity in these populations, and are some populations more diverse than others? Genetic diversity is often based on one or more of the following: heterozygosity, allelic richness and diversity indices such as the Shannon, Simpson, or Nei)
Are there population genetic bottlenecks?
Is there inbreeding?
Are there hybrids (crosses between two species)?
Then of course you have to report some general marker- and population-based stats (Deviation from HWE- Hardy Weinberg Equilibrium, Linkage Disequilibrium (LD), overall expected and observed heterozygosity, (He and Ho), null alleles..etc).
Load the Data: Before you do anything, you have to load the data in a format that the programs recognize!
GenAlex-Excel Based Program-useful to check data formatting, and reformat data for import into R or other programs. However the main thing I found useful was understanding just what your dataframe should look like, which the Poppr tutorial emphasizes nicely: here
For most of my data analyses, I used the following two formats, converting my csv to data that the packages could recognize, or that I could convert further:
#need genclone for gytpes conversion, hence don’t use genclone=FALSE
gtypesdata=genind2gtypes(newdataname2)
Example dataframe for import and analysis with the Poppr R package. Areas selected in blue represent the Loci, Samples and Populations, see poppr tutorial for further examples
Basic and Advanced Stats- I suggest to use:
Poppr– (Kamvar et al., 2015; Kamvar et al., 2014) this package depends on loading a lot of other packages and guides you through analyses in the tutorial. One example- is as a wrapper for the ‘vegan’ package- poppr calculates genotype accumulation curve (see if you sampled enough loci and individuals),
Pegas-(Paradis, 2010) -calculate Linkage Disequilibrium (LD) and HWE across populations for each locus
PopGenReport-(Adamack et al., 2014)- calculate null-allele frequencies pairwise FST and Jost’s D analyses, compare total and average allelic richness (accounting for sample size) and the number of private alleles among populations
diveRsity– (Keenan et al., 2013)-Estimate the average observed (Ho) and expected (He) heterozygosity, deviations from HWE (exact test) and the average ‘inbreeding coefficient’ (FIS) for each population across all loci. In my paper I distinguish FIS as a measure of increases in homozygosity due to genetic drift caused by a larger population being separated into sub populations, rather than due to consanguineous mating (Crow, 2010)
Linear Mixed Models, or Generalized (GLMMs) depending on which is more suitable for your data- with the lmer function in the lme4 package (Bates et al., 2015): I used this to test for the effects of population (collection site) on genetic diversity. Implementing an LMM accounts for the variability of the microsatellite loci by modeling locus as a random effect, and collection site as a fixed effect with allelic richness or expected heterozygosity as the response variables in separate models. Stepwise model simplification (Crawley, 2013) can be performed using likelihood ratio tests. Differences across collection sites can be compared, based on 95% CI, using Tukey’s post-hoc test in the ‘multcomp’ package (Hothorn et al., 2008). Read more about mixed models here.
Analyses of Population Structure
I suggest using several programs to see how they compare. I used:
STRUCTURE -as it is one of the most popular programs-(Pritchard et al., 2000). I used Clumpak (Kopelman, Mayzel, Jakobsson, Rosenberg, & Mayrose, 2015) to analyze the Best K, and to visualize and produce plots based on all of the runs from STRUCTURE outputs. Please see data-wrangling section below for more details on how to get your data into STRUCTURE, and also into Clumpak.
FLOCK- great program in excel (Duchesne & Turgeon, 2012), to see which populations are genetic sources for other populations, as well as determining ‘K’ the number of genetic clusters within a given population or site (useful to compare to output ‘K’s from STRUCTURE
since I have a MacOSX, I had to convert from DOS to UNIX with terminal program before loading in STRUCTURE by using similar code to this: while($_ = <>){s/\r\n|\n|\r/\n/g;print “$_\n”;}
and you can find more info here .
DON’T TOUCH FILE AFTER THIS.. TA DA!
To get my files into the Clumpak web processor, I had to use a different zip-program (Zipfiles4PC) than what the MacOSx does, as for some reason Clumpak couldn’t process- Mac-zipped files.
Ok.. I think that is enough for now.. but really.. If I can emphasize one thing it is to go through the whole Poppr tutorial to get a handle of how to analyze data in R, and a feel for YOUR data!
Wow.. I can’t believe May was my last post.. ugh! Ive been swamped with starting my new postdoc, moving into a new place, and writing an NSF-OCE grant! Anyhow, I am back and will try to be more regular again!
I am excited to announce a new article that ishot off the press! I coauthored this article with Dr. Angelica Reddy (first author) and Dr. Paul Pratt at the USDA, along with researchers from Argentina and Uruguay. You can read it here with free access for 50 days: Article in Biological Control.
This study was in conjunction with some of the work I did as a Delta Science Postdoctoral Fellow to investigate the mechanisms limiting the current biological control of invasive water hyacinth (Eichhornia crassipes) in the Sacramento-San Joaquin River Delta in northern California, USA (hereafter ‘Delta’). Classical biological control uses natural enemies (predators/herbivores, parasitoids and parasites) to control invasive populations of weeds, pests and disease vectors in the introduced range. Successful biological control agents can reduce pest populations below threshold levels that cause problems for humans and native species. Once established, biological control can provide a sustainable, long-lasting management option.
In a previous study, my coauthors and I conducted a one-year field survey 34 years after the initial releases of several biological control agents of water hyacinth in the Delta (Hopper et al. 2017). We found that two biological control agents, the herbivorous weevils, N. bruchi and N. eichhorniae (Coleoptera), were still present in the Delta and the associated tributaries. Although N. bruchi was broadly distributed throughout the Delta, N. eichhorniae was only found in the southernmost tributaries. Densities of N. bruchi during the warmer months in the Delta are comparable to densities in other regions with successful control of water hyacinth, but were not high enough year-round to reduce water hyacinth biomass and cover. Thus one idea to improve control is to re-introduce the more rare weevil, N. eichhorniae, in order to increase its abundance and distribution in the Delta and compliment the impacts of the existing weevil populations.
One theory for the difference in the current abundance and distribution between these two weevil species is that the present biotype of N. eichhorniae in the Delta is less cold-tolerant than N. bruchi. Thus, the researchers from the USDA and myself were interested in determining whether a cold-temperature biotype of N. eichhorniae is present. If a cold-tolerant biotype exists, then the goal will be to screen it in the quarantine (host range tests and pathogen screening), access the necessary permits, and then release it into the Delta to improve the performance of the current population of N. eichhorniae and ultimately enhance the control of the invasive water hyacinth in the Delta.
To achieve these goals, we (Reddy et al. 2019) examined the cool temperature performance and cold tolerance of four populations of the biological control agent, N. eichhorniae. These populations consisted of N. eichhorniae from: the Delta (California: USA), a population within the native range (Uruguay), and two temperate populations (Kubusi River, Stutterheim, South Africa and Jilliby, Australia). The geo-locations of these populations are noted as red markers in the green-highlighted regions on the map.
In this study, we measured life history parameters of these weevil populations under temperatures occurring in the Delta during the cooler seasons (Fall and Winter). These life-history parameters included: Egg survivorship and development, juvenile (larval and pupal) survivorship and development, adult fecundity and adult longevity. I then used these parameters to construct stage-structured matrix models and calculate the intrinsic growth rates, doubling times, generation times and reproductive potential of each of these populations (as I have detailed in a previous blog and linked here).
In summary, Reddy et al. (2018) found that the population from Jilliby, Australia had the highest intrinsic rate of increase under conditions simulating Fall temperatures in the Delta due to the fact this population had the highest fecundity compared to all of the other populations (including the existing population residing in the Delta). Permission is thus being sought to release the Australian population into the Delta to improve the biological control of the invasive water hyacinth.
And I will be back to update you with much more soon, especially on the results from my study on the population genetics of both of these weevils (N. bruchi and N. eichhorniae), using these same populations pictured above and many others! I finally submitted this manuscript for review.. so stay tuned!