The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California

The purpose of this investigation was to evaluate the effect of a small marine reserve (established 1988) on a temperate rocky reef fish assemblage at Santa Catalina Island, California. Fish surveys on SCUBA were conducted at two reserve and two non-reserve sites from October 2002 to January 2004. Sites were similar in fish density, species richness and biomass of the entire fish assemblage. However, the adult densities of two important fishery species, California sheephead (Semicossyphus pulcher; 7.6 0.5 and 5.5 0.4/100 m2 inside versus outside) and kelp bass (Paralabrax clathratus; 3.6 0.4 and 2.9 0.4 inside versus outside), were significantly higher within the reserve. The reserve appears to be effective in increasing density and biomass of two impacted species that were readily observed and surveyed on SCUBA

Effects of Estuary-Wide Seagrass Loss on Fish Populations

Globally, habitat loss in coastal marine systems is a major driver of species decline, and estuaries are particularly susceptible to loss. Along the United States Pacific coast, monospecific eelgrass (Zostera marina) beds form the major estuarine vegetated habitat. In Morro Bay, California, eelgrass experienced an unprecedented decline of \u3e 95%, from 139 ha in 2007 to \u3c 6 ha by 2017. Fish populations were compared before and after the eelgrass decline using trawl surveys. Beach seines surveys were also conducted during the post-decline period to characterize species within and outside of remnant eelgrass beds.While the estuary-wide loss of eelgrass did not result in fewer fish or less biomass, it led to changes in species composition. The post-eelgrass decline period was characterized by increases in flatfish (mainly Citharichthys stigmaeus) and staghorn sculpin (Leptocottus armatus), and decreases in habitat specialists including bay pipefish (Syngnathus leptorhynchus) and shiner perch (Cymatogaster aggregata). There were similar trends inside and outside of remnant eelgrass patches. These findings support evidence across multiple ecosystems suggesting that the predominance of habitat-specialists predicts whether or not habitat loss leads to an overall decline in fish abundance. In addition, loss of critical habitats across seascapes can restrict population connectivity and lead to range contraction. For bay pipefish, the loss of eelgrass in Morro Bay is likely to create a population biogeographic divide. Currently, Morro Bay is dominated by flatfish and sculpins, and the longevity of this new ecosystem state will depend on future eelgrass recovery dynamics supported by ecosystem-based management approaches

Where the Weird Things Are: A Collection of Species Range Extensions in the Southern California Bight

A large-scale monitoring program associated with the establishment of a marine protected area network in southern California provided an opportunity to observe and document unique or rare species across the region. Scientists and students from several educational and research institutions surveyed 145 subtidal reefs, 39 intertidal reefs, and five sandy beaches from 2011-2017, a period of time where oceanographic and climatic conditions changed serially and dramatically. In conjunction with an increase in monitoring frequency and locations, dramatic shifts in oceanographic climate during this same time period likely caused shifts in tolerable habitat conditions for many nearshore species. Here we describe range extensions – both to the north and south – of fourteen marine fish, invertebrate, and algae species as observed during the 2011-2012 South Coast MPA Baseline Program and subsequent monitoring efforts

Predicting Optimal Sites for Ecosystem Restoration Using Stacked-Species Distribution Modeling

Habitat restoration is an important tool for managing degraded ecosystems, yet the success of restoration projects depends in part on adequately identifying preferred sites for restoration. Species distribution modeling using a machine learning approach provides novel tools for mapping areas of interest for restoration projects. Here we use stacked-species distribution models (s-SDMs) to identify candidate locations for installment of manmade reefs, a useful management tool for restoring structural habitat complexity and the associated biota in marine ecosystems. We created species distribution models for 21 species of commercial, recreational, ecological, or conservation importance within the Southern California Bight based on observations from long-term reef surveys combined with high resolution (200 m × 200 m) geospatial environmental data layers. We then combined the individual species models to create a stacked-species habitat suitability map, identifying over 800 km2 of potential area for reef restoration within the Bight. When considering only the 21 focal species, s-SDM scores were positively associated with observed bootstrap species richness not only on natural reefs (linear model: slope = 0.27, 95% CI = 0.17–0.36, w = 1), but also this result was supported by two independent test datasets. The predicted richness from this linear model was associated with observed species richness when considering only the focal species on manmade reefs (linear model: slope = 0.52, 95% CI = 0.13–0.92, w = 1) and also when considering 204 other non-focal species on both natural and manmade reefs in southern California (slope = 3.65, 95% CI = 2.93–4.37, w = 1). Finally, our results demonstrate that the existing manmade reefs included in our study on average are located in regions with habitat suitability that is not only less suitable than natural reefs (t-value = –5.4; p < 0.05), but also only slightly significantly better than random (p < 0.05), demonstrating a need for more biologically informed placement of manmade reefs. The stacked-species distribution model provides insight for marine restoration projects in southern California specifically, but more generally this method can also be widely applied to other types of habitat restoration including both marine and terrestrial

New and Rare Fish and Invertebrate Species to California during the 1997-1998 El Nino

By some measures 1997-1998 El Nino southern oscillation (ENSO) was the strongest such event of the 20 th century and perhaps the strongest of all recorded history. For most of us, an El Nino means increased rains in the Southern California area, due to a disruption of the normal path of the jet stream. In the study of marine ecology and fisheries biology, El Nino\u27s have much more dire consequences. These winter storms can devastate our coastline and are accompanied by unusually warm and unproductive water. El Nino\u27s have been cited as the cause of the collapse of fishery stocks as well as the demise of our world renowned kelp beds. ENSO events have increased in both frequency and magnitude for the past two decades, which has intensified our awareness of this global phenomenon. These changes, which we have seen in our coastal ecosystems, have implications of macroscale changes in oceanography extending far beyond the Southern California arena. As we sit on the precipice of the 21 st century, the staggering ramifications of these new oceanographic conditions trigger questions of global climate change and we are challenged with the prospects of global warming

Revolution and continuity in philosophy: "medievalism" and "modernity"

Este artigo revisa a idéia de filosofia "medieval" and põe ênfase na variedade de significados daquela palavra. O autor crê que necessitamos de uma nova terminologia para aquele período da história do pensamento e sugere, por razões históricas, as expressões "United Age" e "Formation Age". Em todo o artigo prevalece uma tentativa de compreender a natureza da atividade filosófica e da história da filosofi

A Method for Estimating Marine Habitat Values Based on Fish Guilds, with Comparisons between Sites in the Southern California Bight

Habitat valuation is an essential tool for tracking changes in habitat quality and in adjudicating environmental mitigation. All current methods for estimating habitat values of coastal marine sites rely heavily on the opinion of experts or on data variables that can readily be manipulated to influence the outcome. As a result, unbiased, quantitative comparisons between the values of different marine habitats are generally unavailable. We report here on a robust, objective technique for the valuation of marine habitats that makes use of data that are commonly gathered in surveys of marine fish populations: density, fidelity, and mean size. To insure comparability across habitats, these variables are assessed for guilds of fishes, rather than for single species. The product of the three guild-based parameters is transformed to its square root and then summed across all guilds in the habitat, yielding a single measure of habitat value for each site surveyed. To demonstrate the usefulness of this approach, we have analyzed data from existing surveys of 13 marine sites in the Southern California Bight, encompassing 98 fish species from 23 guilds. For seven of the sites, it was possible to develop estimates of the confidence interval of the habitat valuation, using a resampling technique. Variance estimates from resampling in one habitat mirrored those derived from analysis of annual variation. The resultant ranking of habitat types was: kelp beds \u3e shallow artificial reefs \u3e wetlands \u3e protected shallow waters (soft bottom) \u3e shallow open coastal sand (depth \u3c30 m) \u3e soft bottom habitat on the continental shelf (30 m \u3c depth \u3c200 m) \u3e soft bottom habitat on the continental slope (depth \u3e200 m). Although our data sets were restricted to Southern California, similar data could be obtained from any reasonably well-studied marine environment. The guild-based valuation technique may, therefore, be broadly applicable to the analysis of other marine ecosystems

The phylogeny of Paralabrax (Perciformes: Serranidae) and allied taxa inferred from partial 16S and 12S mitochondrial ribosomal DNA sequences

Abstract Partial sequences of 16S and 12S mitochondrial ribosomal DNA were used to examine the phylogenetic relationships of the primarily eastern Pacific genus Paralabrax (Perciformes: Serranidae) and allied taxa. Paralabrax is considered a basal serranine, which is itself considered the basal subfamily in the Serranidae. Multiple serranines reported closely related to Paralabrax from the genera Serranus, Hypoplectrus, Cratinus, and Centropristis were used as outgroups. Species from the remaining two subfamilies, Epinephilinae and Anthiinae, of the Serranidae were also used in the analyses. The tree of the Serranidae was rooted with the families Polyprionidae and Priacanthidae. Paralabrax, the Serranidae, and the Serraninae were monophyletic in this study. Serranus was found to be paraphyletic. Centropristis, formerly considered the sister taxon to Paralabrax, was not closely related in these analyses. Cratinus agassizii, a monotypic genus from the eastern Pacific, was found to be the sister taxon to Paralabrax. There is greater resolution for intergeneric and subfamily relations than interspecific relationships. A single most parsimonious tree for the interspecific relationships of Paralabrax and allied taxa is proposed. This proposed molecular phylogeny is consistent with known biogeographic processes in the eastern Pacific

The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California

Volume: 105Start Page: 128End Page: 14