• Research projects abound from scientists’ studies on aquatic life, glaciers, kelp, otters
By Naomi Klouda
Scientists are keeping an eye out for an invasive European Green crab that has proven to be a problem in other areas.
They set traps for crab near the shore to see what species climb in, and the more people who live and work on the water aware of what this invasive crab looks like can help out.
That’s just one of more than a dozen presentations made available to the public through the Kachemak Bay Research Reserve’s research overviews of projects in the Bay this month. Called “What’s New in Kachemak Bay?” the annual event is a chance to hear about the scientific questions puzzling researchers, presented as a Discovery Lab.
The European Green crab, for instance, has shown up in California and Oregon waters, likely discharged with ship’s ballast water, and it continues a march north.
“We need to be prepared to respond quickly if crab are found. The earlier the eradication starts, the easier it will be to get rid of them,” wrote Catie Bursch, Kachemak Bay Research Reserve Project coordinator. The results so far is that no European Green Crab have been found in Kachemak Bay or Alaska.
The crab is native to Europe and North Africa, but was transplanted to Australia and elsewhere. The crab has made itself at home as far north as British Columbia and is listed among the 100 “world’s worst alien invasive species.”
These are “veracious feeders” who are aggressive and prolific, said Tammy Davis, the invasive species coordinator for the Alaska Department of Fish and Game. “They can quickly displace the native crab species,” she said.
Green crabs resemble tanners somewhat, and literally are greenish at times, and darker to lighter brown.
Here are some highlights from other projects:
• Why do sea otters use certain underwater habitats and not others? Project Leader Nathan Stewart, a Marine Biology Ph.D candidate, UAF SFOS and Brenda Konar, Associate Professor, UAF SFOS set their goal to determine if foraging sea otters use rockier and more complex habitats as opposed to finer grain habitats. They found that foraging sea otters consistently used rockier and more topographically complex habitats. In southern Kachemak Bay they appear to select foraging habitat based on the ease of access to prey and not necessarily on prey abundance or prey quality.
• In another project “Natural Geography In Shore Areas,” project leader Katrin Iken of the University of Alaska Fairbanks conducted a census of marine life from 2003-2010. Its goal was to determine the number, abundance and biomass of species present in coastal habitats using a standard sampling method. It compared data at local (Kachemak Bay), regional (Gulf of Alaska), and global scales, with long term monitoring sites at Cohen Island, Elephant Island, Jakolof Bay, Outside Beach, and Port Graham.
The interesting results from this study show Kachemak Bay rocky intertidal beaches host a high number of species compared to other places around the world. More species of macroalgaeare – large aquatic photosynthetic plants – found in Kachemak Bay than in many other places
• A host of projects relate to salmon monitoring. In one project, a remote video system is used by Ted Otis, Area Finfish Research Biologist, Alaska Department of Fish and Game-CF and Mike Parish, Fishery Biologist, Alaska Department of Fish and Game-CF both of Homer. Their primary goal is to improve the accuracy of salmon escapement monitoring efforts on small streams that don’t warrant the expense of a weir or sonar system. The remote video is capable of providing accurate salmon escapement data on small, clear water streams.
The microwave and satellite transmitters can be used to feed live video from remote locations directly to a biologist’s office computer. Solar, wind, and small hydro-generators can be used to recharge the batteries that power the remote system.
“The time-lapse video recordings of fish passage on remote streams also allow us to monitor additional species of interest (e.g., brown bear, wolverine, river otter, etc.),” they wrote.
• Two separate clam studies are estimating populations of little neck and razor clams. Carol Kerkvliet, Lower Cook Inlet Assistant Area Management Biologist and Mike Booz, Lower Cook Inlet Fisheries Biologist, want to estimate the percent of total clam diggers at Kasitsna, Jakolof and China Poot bays; Bear and Sadie coves; Homer Spit and the remainder of Kachemak Bay, and estimate the number of littleneck and butter clams at beach sites. They found a die-off of littleneck clams in China Poot Bay occurred in 2003 was probably the result of something in the environment like cold temperatures or a decrease in water salinity.
A similar decline in littleneck clams occurred at nearby beaches, maybe from the same cause. Littleneck clam numbers are still low at these beaches.
Booz is also working on the razor clam project, with Kerkvliet. They estimate the number of razor clams at heavily dug beach sections at Ninilchik and Clam Gulch. They found the annual razor clam population ranges from1.4 to 4.4 million at Ninilchik and 2.1 to 9.1 million at Clam Gulch. The annual harvest of razor clams averages 460,000 at Ninilchik and 215,000 at Clam Gulch.
Clam diggers shift annually from one beach to another. In the past few years the majority of the effort occurred at Ninilchik.
They found razor clams at Clam Gulch grow slower than at Ninilchik.
A particularly successful spawning event resulted in a large number of young clams at Ninilchik in 2009. Then a large winter die-off occurred at Ninilchik in November 2010. The number of razor clams there will be estimated in 2011 to examine if abundance was influenced.
• What fish live within kelp forests?Called the “Effects of Habitat Characteristics on the Fish Assemblages of Bull Kelp and Dragon Kelp Forests,” this project by Terril Efird, Marine Biology MS candidate, UAF-SFOS and Brenda Konar, professor, UAF-SFOS was recently completed. They set out to determine how fish communities vary among locations within a kelp forest, with kelp forest size, and with different kelp species.
• A large project is looking at “Planning for a Changing Landscape: Land and Regional Sea Level Changes in the Kachemak Bay Area,” by Angela Doroff, Megan Murphy and Steve Baird, all of the Kachemak Bay Research Reserve, and Jeff Freymueller, UAF Geophysical Institute. Started in 2010, and set to go until 2013, this looks at elevation and changes of salt marsh vegetation as an indicator of the balance between sea level rise and land level change. The goal is to refine models to better predict uplift rates and to calculate estimates of regional sea level rise.
“We are just beginning the study and will be building upon data histories from KBRR and UAF,” they write.
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