Marks et al.: CHaNGes IN sIZe aND aBUNDaNCe OF FIsHes IN CeNtral CalIFOrNIa aFter a DeCaDe OF FIsHING ClOsUres

rockfish Conservation areas (rCas) were implemented in 2000 to 2003 along the West Coast of the united states to reduce fishing mortality on rockfish (Sebastes spp.) and other groundfish species that had recently been declared overfished. in 2012, we initiated a study to compare recent catch rates, species compositions and length frequencies of fishes inside and outside the rCas with data collected in central California between 1995 and 1998. at all sites surveyed, total catch rates from the new surveys (2012–14) were significantly higher than catch rates from before rCa implementation (1995–98). The majority of the differences were due to the increased relative abundance of yellowtail rockfish (Sebastes flavidus), although other species, including the overfished canary rockfish (Sebastes pinniger), also increased. differences in the size composition of species between the two time periods reflected both the increased survival of older fishes and higher recruitment success in the past decade. INtrODUCtION after receiving subsidies to develop domestic fishing capability in the 1970s, the us West Coast fishing fleet became overcapitalized in the 1980s, resulting in fishing mortality rates that were unsustainable (ralston 2002; Melnychuk et al. 2013). as a consequence of the combined effects of overexploitation and poor recruitment conditions throughout the 1990s, seven species of rockfish (Sebastes spp.), as well as lingcod (Ophiodon elongatus) and Pacific hake (Merluccius productus) were declared overfished in West Coast waters during the late 1990s and early 2000s (berkeley et al. 2004; PFMC 2003). in an effort to protect and rebuild overfished species, while allowing for some harvest of healthy stocks, a broad set of spatial area closures was implemented between 2000 and 2003 to minimize fishing mortality on rebuilding species. These areas are known as rockfish Conservation areas (rCas), i.e., areas on the continental shelf and slope closed to specific recreational and commercial fishing activities. in us waters, the rCas extend along the entire West Coast from the Mexican border to the Canadian border, and fishing prohibitions continue to date. The regulatory boundaries of rCas are lines that generally follow depth contours. The precise boundaries vary both over time (season and year), gear type used, and by latitude in different areas of the coast. recreational fisheries have been constrained to waters shallower than the nearshore boundary of the recreational rCa, while both trawl and fixed gear commercial fisheries are allowed to fish deeper than the seaward boundary of the trawl and non-trawl rCas (Mason et al. 2012). in California, the recreational rCa has been divided into a number of management areas, such that fishing for groundfish species has been prohibited deeper than 36–110 m (20–60 ftm) on the continental shelf. although rCas are not intended to exclude fishing on a permanent basis, they are intended to provide the benefits of spatial closures often attributed to marine reserves, primarily the severe reduction of fishing effort to rebuild overfished species. some of these benefits include general increases in population size and biomass, increases in the mean length of fish, and higher reproductive potential (lester et al. 2009). The latter benefit can occur in situ through increased fish abundance as well as reduced mortality from fishing of larger, older fishes, which may contribute disproportionally to reproductive success (hixon et al. 2014). in addition, enhanced reproductive potential within a closed area is expected to have “spillover” effects, seeding adjacent areas with both emigrating adults and dispersing progeny from the protected spawning population. recent studies have evaluated population trends before and after rCa closures using a combination of Marks et al.: CHaNGes IN sIZe aND aBUNDaNCe OF FIsHes IN CeNtral CalIFOrNIa aFter a DeCaDe OF FIsHING ClOsUres CalCOFI rep., Vol. 56, 2015 120 CdFW observers recorded a latitude and longitude for fishing drifts, the number of active anglers, fishing time, number of each species caught, and whether they were kept or released. This enabled calculations of catch per unit effort (CPue) for discrete geographic areas. observers recorded total length (mm) of a subset of retained fishes on the vessel while transiting to port. Thus, length data from 1987–98 do not have associated latitude and longitude coordinates on the fine geographic scale of a fishing drift. as a result, we only compared lengths of fishes from the 1987–98 data set from fishing trips that occurred exclusively at the locations that were sampled in 2012–14. although the CdFW 1987–98 data have been used to support past stock assessments, information on catches at a greater spatial resolution were recovered as a component of this effort and recently uploaded in 2014 into a relational structured queried language (sQl) database. 2012–14 Fishing Methods Field methods for the 2012–14 surveys followed fishing operations in the 1987–98 CdFW surveys with the exception that we released caught fishes, targeted specific locations where 1987–98 surveys took place, and recruited volunteer anglers. although the end tackle used by fishers surveyed in the CdFW study was not precisely recorded, discussions with CPFV captains suggested that five-hook shrimp-fly gangions was the gear most commonly used at the time. Therefore, five-hook gangions with shrimpfly lures were provided for each angler and no subtractions or additions of gear were allowed to enable the calculation of catch rates on a per-hook basis in future comparative studies. half of the anglers used strips of squid bait on each hook and the other half did not use bait to represent different methods of fishing. Captains were instructed to conduct fishing drifts as they would on a normal chartered day of fishing. gPs coordinates of CdFW fishing locations were provided to locate areas for fishing to occur. once in those areas, captains searched for locations to fish, making use of depth sounders as well as their knowledge of the fishing grounds. Captains started and stopped fishing based on drift speed and catch rates, as they would on normal trips. start and stop times for each drift were recorded to calculate CPue. beginning and ending coordinates were recorded and later plotted in gis to track drift lines in relation to rCa boundaries as well as compare our fishing locations with the CdFW fishing data. each day consisted of approximately three hours of fishing within the region. To ensure fish survival upon release, each fish caught was initially placed into an 18-gallon bin filled with fresh seawater. Care was taken to minimize damage to each fish while the hook was removed. Fish were identified to species and we measured fork length to the nearest halfonboard observer data for recreational fisheries in areas open to recreational fishing (e.g., Cope et al. 2013) and data from bottom trawl surveys (e.g., keller et al. 2014). While keller et al. (2014) documented greater catch rates and larger fish within rCas for a suite of demersal species, their data set did not include information from the time period prior to rCa establishment, contained minimal coverage of shallower regions targeted by recreational fisheries, and excluded high relief habitats that are inaccessible to trawling. Thus, there remains a need to better quantify changes in the relative abundance of rocky reef fishes in nearshore waters to understand the effects of area closures at fine spatial scales. a temporally and spatially extensive pre-rCa data set made it possible to assess the effectiveness of the rCas after a decade of spatial closures. From 1987 to 1998, in response to industry concerns of an apparent decline in the quality of fishing for rockfishes and lingcod in central and northern California waters, the California department of Fish and Wildlife (CdFW) conducted at-sea sampling of the catch of commercial passenger fishing vessels (CPFVs) (reilly and Wilson-Vandenberg 1999). during that period, observers accompanied charter-fishing vessels on over 2,200 fishing trips that targeted rockfishes and lingcod, collecting information on over 300,000 fishes. They recorded fishing effort (in units of angler hours spent fishing), species composition, lengths, and coarse fishing location information in every month of the year at sites from Morro bay to eureka, Ca. The goal of our research was to evaluate changes in species compositions, catch rates, and lengths of recreationally important species within three different regions of central California in pre-rCa and post-closure data sets. This research was a collaborative effort among the national Marine Fisheries service (nMFs), CdFW, Moss landing Marine laboratories (MlMl), California sea grant, the central coast CPFV fleet and volunteer anglers recruited through the California Collaborative Fisheries research Program at MlMl for the postclosure surveys. here we compare fishery metrics calculated from the pre-rCa CdFW data set (1995–98) to a new post-closure data set (2012–14) that was generated by fishing in the same locations and using protocols and techniques similar to those used by reilly and Wilson-Vandenberg (1999) during the CdFW surveys.