Project Title: AKCSI Project 4. Productivity of fishery management plan (FMP) species in coral and sponge habitats in the Alaska region
Project Summary

A comparative approach will be utilized to examine the productivity of FMP species found within two biotic (coral and sponge) complex habitats and one non-biotic (boulder, rocky) complex habitat located within the central and/or western Gulf of Alaska.  

Anticipated Management Application(s)

The 2007 enactment of the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 included a requirement to establish a deep sea coral research program. Identified data needs to improve management of coral and sponge ecosystems include both a better understanding of the biodiversity and ecology of coral communities and the impacts caused by fishing and human activities (NOAA 2010). Many commercially important species have been found to be associated with coral and sponge habitats in Alaska waters. Survey data for this region indicate rockfish and Atka mackerel are associated with gorgonian, cup, and hydrocorals and flatfish and gadoids are more commonly associated with soft corals (Heifetz 2002). A study in the Aleutian Islands using fine scale video monitoring of the seafloor found that a significant fraction of the commercially important fish and crabs were associated with corals and other biotic structures. All rockfish observed during the study were highly associated with corals (Stone 2006). Coral and sponge habitats may be particularly important for both juvenile and adult rockfish. The CPUE of juvenile Pacific ocean perch captured in trawl surveys in the Gulf of Alaska is positively correlated to the CPUE of sponge and coral (Rooper and Boldt 2005). In southeast Alaska juvenile rockfish have been shown to be associated with sponges (primarily Aphrocallistes) (Freese and Wing 2003) and adult rockfish have been shown to be associated with coral of the genera Primnoa (Krieger and Wing 2002). These complex habitats are likely providing both protection from predators and increased prey availability. The relative importance of coral and sponge habitat as compared to other non biotic complex structure (e.g. boulders) for rockfish and other FMP species remains unknown. The vulnerability of these habitats to fishing gear (Heifetz et al. 2009) is of concern and further emphasizes the need to better understand these ecosystems. The overarching goal of this study is to examine the productivity of FMP species within coral and sponge habitats in the Gulf of Alaska.  

Location(s):
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Point of Contact: Office of the Point of Contact:
  • NMFS AFSC
Project Title: AKCSI Project 4. Productivity of fishery management plan (FMP) species in coral and sponge habitats in the Alaska region
Methods/Approach

A comparative approach will be utilized to examine the productivity of FMP species found within two biotic (coral and sponge) complex habitats and one non-biotic (boulder, rocky) complex habitat located within the central and/or western Gulf of Alaska.  The specific objectives of the project include:

  1. To determine and compare the community structure and density of FMP species within each locality and to examine the proximity of individual fish to complex structures within the habitat.
  2. To assess the role of complex habitat both biotic and non-biotic as Essential Fish Habitat for FMP species found within each locality.
  3. To examine and compare the diet, condition, and energetic content of fish found within each sampling site.
  4. To assess the predator/prey relationships by examining prey availability and potential predators at each location.
  5. To examine the reproductive potential of adults at each location.

In order to accomplish these objectives we propose to conduct an eleven day sampling cruise during each year of the study.  During each cruise we will sample at two identified sponge/coral habitat sites and one rocky/boulder habitat site that does not contain living structure. We will utilize a video camera system to examine habitat associations, community structure, and density within these areas. At each site at minimum of four video transects of approximately 2 km will be towed depending on study site characteristics. After the camera is retrieved a bottom trawl will be utilized to confirm species identification and size of fish within the habitat. Trawl samples will be utilized to examine diet, energetic content, and reproductive status of individual fish within the habitat. At each site a plankton net will be deployed up to four times to capture zooplankton and examine the prey field available at each locality.

Video camera operations and data analyses will be patterned after Rooper et al. (2007). The video camera system will incorporate underwater lights and stereo video cameras to estimate the size and distance to objects observed in the video. The camera sled will be towed or drifted at slow speeds (1-3 knots) maintaining position 1-2 m above the seafloor. Video from the camera system will be recorded for later analysis. The non-biotic habitat will be classified as mud, sand, pebble, cobble, boulder, low exposed bedrock, or high relief bedrock according to the methodology of Stein et al. (1992) and Yoklavich et al. (2000). Biotic habitat will be classified to genera and where possible to species. Fish species will be documented as well as the number of each species observed. The habitat associations of FMP species will be determined by measuring the distance of each fish to nearby structure within the habitat. Bottom trawl catches will be sorted to species and weighed. For the predominant FMP species within the catch, lengths will be measured, stomach samples will be preserved, reproductive samples will be preserved from adult fish, and a sub-sample of fish will be immediately frozen for future energetic and condition analyses.

During the upcoming year additional funding will be pursued for an additional sampling cruise during a second period of the year. An additional cruise will allow us to examine temporal changes in community structure and productivity at the same localities. 

Project Results and Management Outcomes  None Defined
Project Title: AKCSI Project 4. Productivity of fishery management plan (FMP) species in coral and sponge habitats in the Alaska region
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