How Ocean Acidification Impacts Lobster Larvae

Maine School of Marine Sciences, by Ian Jones, April 15th 2014

Third-year marine sciences major  Ian Jones of Canton, Conn., is studying how ocean acidification impacts lobster larvae, an important resource for the Maine economy.

Jones works with American lobsters raised at UMaine’s Aquaculture Research Center (ARC). The lobster larvae were raised last summer at various pH levels, replicating natural environments and the impact of ocean acidification. Jones weighed and photographed approximately 700 lobster larvae to monitor their growth in these different environments. The hypothesis: slower growth and more irregular development occur at lower pH. This creates adaptation problems for lobsters dealing with increased environmental CO2 levels.

“We will certainly see greater ocean acidification in the future as an effect of climate change. As atmospheric levels of CO2 continue to increase from human input, so do the CO­2 levels of the upper ocean,” says Jones.

Along with lobster larvae, Jones also monitored seahorses in Tim Bowden’s lab. The seahorses, which were dealing with a mycobacterial infection, were in the care of Jones while an antibiotic treatment was created. He also raised juvenile seahorses last year. Through this experience, Jones learned about seahorse aquaculture, proper feeding protocols, tank chemistry and more.

“Not much is known about seahorse aquaculture relative to raising other fish, so although information on raising newborns was limited, it was a fun challenge figuring out our own system that worked.”

This fall, Jones will travel to the Darling Marine Center on the Damariscotta River, where he and other UMaine students will further the hands-on work they do in the classroom through the Semester By the Sea program.

Jones plans to attend graduate school to study sensory biology and/or the effect of climate change on marine animals.

Why is your lobster research important? Research on American lobster growth at lowered pH is incredibly important first, because there has been little climate change study on this particular species and second, any slowing or other adverse effects on lobster growth could have serious impacts on the health of the lobster fishery, which Maine, of course, greatly depends on. Delayed lobster larvae development means it will take longer for lobsters to get to market size, and predation risk may increase as well, causing fewer individuals to grow into adults and lowering the overall abundance of adult lobsters. Changes in lobster abundance can in turn upset ecosystem balance by changing the abundance of organisms that depend on lobster as prey and organisms lobsters prey on. These trophic cascades have the power to reduce the presence of many species in addition to just the lobster, consequently reducing biodiversity.

Read more here

Ocean Acidification Impairs Vermetid Reef Recruitment

Feb 28th, 2014, Nature.com

Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems.

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Mediterranean vermetid reefs.

(A) A pristine vermetid reef at low tide in NW Sicily, Italy. (B) Collection of a vermetid core in the outer rim of a vermetid reef; black spots are the shell openings of Dendropoma petraeum cemented by the coralline alga Neogoniolithon brassica-florida. (C) A vermetid core transplanted in the intertidal off Vulcano Island. (D) A recruit newly settled on the coralline alga (top left) and the shell opening with the operculum of a D. petraeum adult (below). Photo credits: R.C. (A); M.M. (B,C); M.M. and M.F. (D)