Map of the main Hawaiian Islands with Bottom Restricted Fishing Areas (BRFAs) indicated with orange/brown diagonal stripes
Hawaiian "Deep 7" Bottomfish images form the BotCam
BotCam equipment and deployment
Click above to visit the DAR website
Click hereto watch a video of research results aired on the DLNR Revealed Series
Friedlander AM, Stamoulis KA, Kittinger, JN, Drazen JC, Tissot BN (2014) Understanding the scale of marine protection in Hawai'i: from community-based management to the remote northwestern Hawaiian Islands. Advances in Marine Biology 69:153-203. pdf
Sackett DK, Drazen JC, Moriwake VN, Kelley CD, Schumacher BD, Misa WFXE (2014) Marine protected areas for deepwater fish populations: an evaluation of their effects in Hawaii. Marine Biology 161:411-425pdf
Misa WFXE, Drazen JC, Kelley CD, Moriwake VN (2013) Establishing species-habitat associations for 4 eteline snappers with the use of a baited stereo-video camera system. Fishery Bulletin 111:293-308pdf
Moore CH, Drazen JC, Kelley CD, Misa WFXE (2013) Deepwater marine protected areas of the main Hawaiian Islands: establishing baselines for commercially valuable bottomfish populations. Marine Ecology Progress Series 476: 167-183pdf
Sackett D, Drazen J, Vaz A, Moore C (2012) Bottomfish Restricted Fishing Areas and the deep 7: a report of current monitoring results. Bottomfish News 14: 2-3pdf
Merritt D, Donovan MK, Kelley C, Waterhouse L, Parke M, Wong K, Drazen JC (2011) BotCam: a baited camera system for nonextractive monitoring of bottomfish species. Fishery Bulletin 109: 56-67 pdf
Drazen JC, Moriwake V, Demarke C, Alexander B, Misa W, Yeh J (2010) Assessing Kaho‘olawe Island Reserve's bottomfish populations: a potential benchmark for main Hawaiian Island restricted fishing areas. prepared for the Kahoolawe Island Reserve Commission
This project was funded by the State of Hawaii Department of Land and Natural Resources - Division of Aquatic Resources and in part by
the Federal Aid in Sport Fish Restoration Program.
The deep water bottom fishery in Hawaii represents an ecologically important resource that is exploited both commercially and recreationally. Unfortunately, as is the case with most fisheries, the main Hawaiian Islands (MHI) bottom fishery has been over-exploited. In 1997 the State’s Department of Aquatic Resources (DAR) implemented a bottomfish management plan that created 19 bottomfish restricted fishing areas (BRFAs) where bottomfishing was prohibited. This system was reviewed and found inadequate in 2005. On July 1, 2007 a new BRFA system was developed which took advantage of a greater knowledge of the distribution of MHI bottomfish habitat. The new management system implemented 12 BRFAs (Appendix A) which were selected to both protect selected habitat and to facilitate the recovery of exploited stocks.
Fisheries biologists at DAR and NOAA’s Pacific Island Fisheries Science Center have emphasized the importance of maintaining baseline and monitoring data on fisheries stocks to assess the efficacy of the new BRFA system. As part of this effort, in 2007 the Bottomfish Project was initiated. The goal of this project was to monitor the bottomfish populations within a representative subset of 6 BRFAs over a 5-year time period to assess the population impacts of the restricted fishing regulations of the BRFAs. These BRFAs are monitored by deploying baited bottom cameras (BotCams) at randomly selected locations within and outside of the BRFAs in depths of 100-300 meters. The BotCams use only the ambient light and record ~ 45 minutes of activity using a pair of cameras so stereoscopic imagery is available for fish measurements. The goal of the BotCam analysis is to assess the efficacy of BRFAs in rehabilitating the MHI bottomfish stocks (changes in relative abundance and sizes).
From 2007 to 2015, BotCams were deployed in and around seven of the 12 BRFAs as well as inside the boundaries of the Kahoʻolawe Island Reserve. Relative abundance, or the maximum number of each species observed in a single frame of video, was determined for more than 1,650 deployments and 4,760 Deep 7 bottomfish were measured. Of the four BRFAs monitored for several years between 2007 and 2011, mean fish length, and in some cases abundance, increased for one or more of the most economically important target species (onaga, opakapaka, and ehu) inside nearly all BRFAs, but declined or stayed the same outside. These changes over time suggest protection had an effect on the bottomfish population. Results from continued monitoring of two of these BRFAs (Penguin Bank and Makapuʻu) suggest that Deep 7 species inside these reserves may have begun to spillover the boundary of the BRFAs into neighboring fished areas in the fifth and sixth years of sampling. An increasing number of trends over the years show relative abundance, fish size, and species richness (number of Deep 7 species observed in a deployment) declined with distance from BRFA; the BRFAs may have been a source of more and larger fish in later years. In the eighth sampling year and coincident with confusion over the status of the BRFAs, many of the significant spatial trends at the Penguin Bank BRFA disappeared and may indicate that the benefits of these areas can dissolve relatively quickly when left unprotected.
In addition to the fishery-independent assessment of Deep 7 species, our research resulted in a greater understanding of species-specific habitat preferences and how those preferences may change over the lifespan of the species. This information is valuable for making informed management decisions and can help in the refinement of essential fish habitat designations and BRFA design and placement. See the references below for more detailed information on the results of our studies.