Current Shellfish Assessment (Kodiak) Research
Annual Eastern Bering Sea Crab Survey
Stocks that NOAA Fisheries is responsible for assessing are covered by the Bering Sea/Aleutian Islands King and Tanner Crab Fishery Management Plan (NPFMC 1998). Crabs surveyed
include snow crab (Chionoecetes opilio), Tanner crab (Chionoecetes
bairdi), two stocks of blue king
crab (Paralithodes platypus), red king crab (Paralithodes camtschaticus) and hair crab
(Erimacrus isenbeckii).
These surveys are conducted in three legs throughout the summer with two vessels dedicated to each leg.
The EBS survey is augmented every year by the addition of
special projects.
Small-Mesh Nearshore Gulf of Alaska Trawl Survey
This survey has been conducted with standard methods since 1972 by staff from the
Kodiak Lab in collaboration with the Alaska Department of Fish and Game, and is the
longest continuous annual survey of its type in the North Pacific. This time series has
been instrumental in describing ecological change in the Gulf of Alaska following the
1976 climate regime shift in the North Pacific (Community reorganization in the Gulf of Alaska following ocean climate regime shift. P. J. Anderson, J. F. Piatt. 1999.)
and in describing ecological response to more recent climate change (Climate regime shifts and community reorganization in the Gulf of Alaska: How do recent shifts compare with 1976/1977?. M. A. Litzow.
2006. ICES Journal of Marine Science 63:1386-1396.). For information, contact Robert Foy.
Culture of Red King Crab Larvae
as a Means to Facilitate the Release of Juveniles into the
Ocean Environment.
In partnership with Alaska Sea Grant and other agencies, community organizations, and industry, Sara Persselin is the lead biologist on this Alaska Sea Grant sponsored Alaska King Crab, Rehabilitation and Biology Program (AKCRRAB). The goal of this multi-year project is to initiate mass rearing of larval red and blue king crabs in the Alutiiq Pride Hatchery in Seward, AK. The first year of this project would be devoted to mass or optimal culture of king crab larvae under hatchery conditions. This initial step is critical toward determining feasibility of the project. In addition, optimal release densities will be determined and larval collection devices in Chiniak Bay and possibly Alitak Bay will be deployed to determine where larval king crab are
being transported after release.
Developing Biological Reference Points for Crustacean Fisheries: Reproductive
Potential of Bristol Bay Red King Crab and Eastern Bering Sea Snow Crab.
The North Pacific Research Board (NPRB) awarded Katherine Swiney of RACE Shellfish, and Ginny Eckert, Ph.D.and Gordon Kruse, Ph.D. of the University of Alaska, Fairbanks a four year grant to conduct concurrent laboratory experiments and field collections of Bristol Bay red king crab (BBRKC) and eastern Bering Sea snow crab (EBSSC) to achieve three project objectives which are important for improving assessment of reproductive potential and understanding population dynamics for these two stocks. The objectives are to: (1) assess reductions in fecundity during brooding and occurrence of unfertilized or non-viable eggs (2) assess egg quality by female size and reproductive history and (3) assess larval fitness by female size, reproductive history, and egg quality. The incorporation of reproductive potential in the development of biological reference points is a pressing fishery management need for Bering Sea crab stocks. A review by the Center for Independent Experts (CIE) determined that a quantitative understanding of the contribution of female crabs of differing life histories are needed to replace the current, crude measure of reproductive output based on total female biomass.
Predicting Snow Crab Growth and Size with Climate Warming in the Northern Bering Sea.
Louis Rugolo, Ph. D., is a collaborator with Prinicipal Investigator, James Lovvorn, University of Wyoming, on this NPRB funded project to explore the relationship of water temperature with the distributions, growth, and reproduction of snow crab in the northern Bering Sea. In the Bering Sea, the main concentration of snow crabs of marketable size has shifted northward from Bristol Bay to northwest of St. Matthew Island, with further expansion likely. To test the hypothesis that crab size structure and viable fisheries in the northern Bering Sea are controlled by temperature effects, they will compare model predictions of growth and size structure to data from the study area, and to historical data from the Chukchi Sea and north of St. Matthew Island.
Ocean Acidification Effects on Larval Crab
Carbon dioxide from the atmosphere is taken up by the world’s oceans, making them more acidic and changing the availability of dissolved calcium for animals, like crabs, that use calcium to harden their exoskeletons. Sara Persselin and Katherine Swiney are working with Jeff Short of the Auke Bay Lab to raise larval king crab under different acidity conditions in order to better understand the effects of ocean acidification on commercially important crab stocks.
Read more...
Dive Program
Peter Cummiskey and
Eric Munk coordinate the year-round underwater research in Women's Bay near Kodiak
to study in situ the growth of red king and Tanner crabs, their behavior and habitat relationships,
and the timing of molting and grasping. Join an exciting dive to locate and
track the movements of a red king crab pod.
Crab Cultivation and Embryonic Development Research
Larval crab cultivation plays a very important role in supporting early life history research at the Kodiak
facilities on such species as red king crab, blue king crab, snow crab,
Tanner crab, Hairy crab (Hapalogaster mertensii). Currently, the golden king crab (Lithodes aequispinus) project is in progress under the guidance of Scott Van Sant. In addition to studies on improving methods for
cultivating crab larvae, Sara Persselin and others study hatch timing and survival of
larvae under different conditions. Future research aims to improve the
cultivation methods and technology for crab larvae, look at the settlement behavior by crab
larvae and the use of critical habitats, and cannibalism/predation levels of
settling crab. Several posters have been presented :
- Settling
Behavior and Substrate Preferences of Red King Crab (Paralithodes camtschaticus)
Glaucothoe (334KB pdf) in 1998 at the
International Crustacean Congress(4th) in Amsterdam by Dr. Bradley Stevens.
- Observations on the Reproductive Biology of the Hairy Crab Hapalogaster mertensii, on Kodiak Island, Alaska(4.7MB pdf) by Susan Payne, Jan A. Haaga, and Dr. Bradley Stevens, at the National Shellfisheries Association 98th Annual Meeting, Monterey, CA, Mar 2006.
- The
Seawater System Design for Broodstock and Laboratory Cultivation of Blue King
Crab Paralithodes platypus Larvae(323 KB pdf poster; zoom in for best viewing) at the 2003 Alaska AFS meeting by Sara Persselin and Scott Van Sant.
- Cultivation of Blue King Crab Larvae, Paralithodes platypus:
Effects of Diet, Temperature, and Density (7MB pdf poster) at the
4th Fish and Shellfish Larviculture Symposium in Ghent,
Belgium in September 2005 by Sara Persselin and the 2005 Lowell Wakefield Fisheries Symposium by Dr. Bradley Stevens.
- Embryonic
Development of Pribilof Island Blue King Crab, Paralithodes platypus,
Studied Using Image Analysis and Clustering Procedures by Dr.
Bradley Stevens at the Marine Science in Alaska 2006 Symposium, Anchorage, AK, January 2006 and has been recently published (Journal of Shellfish Research, Vol. 25, No. 2., 569-576, 2006).
- Hatch timing, incubation period, and reproductive cycle for captive primiparous and multiparous red king crab, Paralithodes camtschaticus.
Stevens, B. G., and K. M. Swiney. 2007. J. Crustacean Biol. 27:37-48.
Primiparous and Multiparous Tanner Crab Egg Development
Work in Woman's Bay, Alaska suggest that females carrying a clutch of eggs for the first
time (primiparous) brood their eggs for many months longer than females that have
previously brooded egg clutches (multiparous). In this study, Katherine
Swiney is examining
egg development monthly between primiparous and multiparous females from extrusion to
hatching. Through the course of this study, Kathy will also be able to confirm when
primiparous and multiparous females extrude egg clutches and when their eggs hatch.
Spawning Preferences of Capelin and Pacific Sandlance
With the help of community volunteers, the preferred spawning beaches of Capelin (Mallotus villosus)
and P. sandlance (Ammodytes hexapterus) are identified.
Susan Payne will look at the hydrographic and astronomical data
as well as other conditions surrounding these beach spawning events to identify optimal conditions for
spawning. If you are interested in volunteering your beachcombing skills to aid
this project, please see the
Beachcombers Alert poster (416KB pdf) for instructions.
Past research and our mission here in Kodiak.
Note: Some reports are PDF documents, and may take a long time to download if you use a dial-up connection. See
our accessibility information for links to assistive
Adobe software.
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