Hello Low-low tides, your presence in the bay means we’re back in the field so I love you very much. Fieldwork is my favorite, it's a mix of appreciation, wonder, and constant problem-solving. Aside from maintaining the traps for green crab monitoring while out in the field, I try and sneak in some time to look under rocks, learn the names of new plants, get stuck in the mud and ask questions about tube worms, tidal patterns, the strength of tuna blood for scent dispersal in tidal waters, and so on. I've been working alongside Shon and Sebastian this week, doing our monthly monitoring of the invasive European green crabs (Carcinus maenas) at our regular ten survey sites. The traps we set out caught some native species including Oregon shore crabs (Hemi nudis), Dungeness crab (Metacarcinus magiste), and sculpin, but the majority of our catch was the green crab. Thursday’s catch had the largest (worst) numbers for green crab abundance this year with one of our sampling sites reaching a whopping 92 green crabs in just six nets… that's a lot. The good news is that most of the European green crabs (EGC) we are catching seem to be adults. This means it may be a low year for recruitment (the new population added via reproduction, immigration, or emigration). A low year of recruitment isn't necessarily a sign that the EGC population in Coos Bay is dying out since most of our largest recruitment events are tied to El Nino years, but it is a good sign for our local crab fisheries and eelgrass restoration projects for the moment. Speaking of Eelgrass... On Friday, I assisted in some eelgrass monitoring with Ali Helms and her REU intern, Chloe. There was a big die-off of eelgrass a few years back so restoration efforts have been underway to re-establish the lost beds throughout the bay. Eelgrass is finicky, the loss of rooted eelgrass plants in the sediment means that the feedback loop that results in good sediment for eelgrass seed germination is also gone, making restoration efforts tricky. Because eelgrass is a key habitat plant for juvenile Dungeness crabs, efforts continue, and from what I was able to see, transplanted eelgrass from healthier beds have been showing signs of success!
It’s been a good and busy week. I’ll be spending my Saturday vegging out so I'll be rested for Sunday’s Slough-a-thon! I’m the kayaking leg of a relay team with Shon and Sebastian (Team name: Lean Mean Green (Crab) Team)! Wish us luck!
1 Comment
Annika
7/21/2022 04:25:31 pm
Awesome photos, the fieldwork looks really fun!
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AuthorHello! My name is Colleen Walker. I'm a New Yorker now living in Oregon where I am pursuing an AS in Biology at Clackamas Community College. This summer I'll be studying the European green crab alongside Dr. Shon Schooler at the South Slough National Estuary Research Reserve. Archives
August 2022
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