Channel Islands National Park kelp forest monitoring program: Annual report 2015

Sprague, Joshua; Moore, Kelly; McClain, Jaime; Molitor, Cullen; Kushner, David

doi:10.36967/nrr-2288646

Channel Islands National Park (CHIS) has conducted long-term ecological monitoring of the kelp forests around San Miguel, Santa Rosa, Santa Cruz, Anacapa and Santa Barbara Islands since 1982, this being the 34th year of monitoring. The original permanent transects were established at 16 sites between 1981 and 1986 with the first sampling beginning in 1982. An additional site, Miracle Mile, was established at San Miguel Island in 2001 by a commercial fisherman with assistance from the park. Miracle Mile was partially monitored from 2002-2004, and then fully monitored (using all KFM protocols) since 2005. In 2005, 16 additional permanent sites were established to collect baseline data from inside and adjacent to four marine reserves that were established in 2003. Sampling results from all 33 sites mentioned above are included in this report. Funding for the Kelp Forest Monitoring Program (KFM) in 2015 was provided by the National Park Service (NPS). The 2015 monitoring efforts utilized 53 days of vessel time to conduct 956 dives for a total of 1005 hours of bottom time. Population dynamics of a select list of 71 “indicator species” (consisting of taxa or categories of algae, fish, and invertebrates) were measured at the 33 permanent sites. In addition, population dynamics were measured for all additional species of fish observed at the sites during the roving diver fish count. Survey techniques follow the CHIS Kelp Forest Monitoring Protocol Handbooks (Davis et al., 1997, and Kushner and Sprague, in progress). The techniques utilize SCUBA and surface-supplied-air to conduct the following monitoring protocols: 1 m2 quadrats, 5 m2 quadrats, band transects, random point contacts, fish transects, roving diver fish counts, video transects, size frequency measurements, and artificial recruitment modules. Hourly temperature data were collected using remote temperature loggers at 32 sites, the exception being Miracle Mile where there is no temperature logger installed. This annual report contains a brief description of each site including any notable observations or anomalies, a summary of methods used, and monitoring results for 2015. All the data collected during 2015 can be found in the appendices and in an Excel workbook on IRMA. Roving diver fish count (RDFC), fish size frequency, natural habitat size frequency, and Artificial Recruitment Module (ARM) size frequency data are now stored on IRMA at https://irma.nps.gov/DataStore/Reference/Profile/2259652. The status of kelp forests was notably different between the five Park Islands. This is a result of a combination of factors including but not limited to, oceanography, biogeography and associated differences in species abundance and composition, as well as sport and commercial fishing pressure. All 33 permanent sites were established in areas that had or were historically known to have had kelp forests in the past. In 2015, 17 of the 33 sites monitored were characterized as developing kelp forest, kelp forest or mature kelp forest. In addition, four sites were in a state of transition. One site was part kelp forest and part dominated by Ophiothrix spiculata. One site was dominated by Sargassum horneri. Seven sites were dominated by echinoderms which were down from 10 sites in the previous year. The remaining three sites were characterized as barren areas, two if which had moderate to high abundances of Strongylocentrotus spp. Overall, the number of sites characterized as kelp forests increased two from last year, and the number of sites characterized as being dominated by echinoderms decreased. There have been dramatic changes at several Santa Barbara Island sites occurring over the last three years. The changes occurring at Graveyard Canyon and Southeast Sea Lion last year continued this year, with both sites continuing to have kelp forests, as well as noticeable decreases in Strongylocentrotus spp. Additionally, Webster’s Arch has transitioned into kelp forests. Arch Point...

Channel Islands National Park kelp forest monitoring program: Annual report 2015

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