3736 research outputs found
Sort by
Critique de l’État et politiques de l’émancipation : à propos de deux ouvrages de Andrea Cavazzini
No full text
California Records of the Oarfish, Regalecus russelii (Cuvier, 1816) (Actinopterygii: Regalecidae)
Full text linkAsemichthys taylori Gilbert 1912, Spinynose Sculpin, New to the California Marine Fauna
Full text linkThe Panamic Fanged Blenny, Ophioblennius steindachneri Jordan & Evermann, 1898, New to California Marine Waters with a Key to the California Species of Blenniidae
Full text linkWhere the Weird Things Are: A Collection of Species Range Extensions in the Southern California Bight
Full text linkA 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
Investigating the disappearance of short-finned pilot whales (Globicephala macrorhynchus) from Southern California: Did fisheries play a role?
Full text linkThere is a mystery surrounding the disappearance of short-finned pilot whales (Globicephala macrorhynchus) from southern California. This species was very common in these waters through the early 1980s, with an apparently seasonally-resident population centered around Santa Catalina Island in the southern California Bight. From 1980-1985, pilot whale numbers off Catalina Island declined dramatically, and they eventually disappeared. One theory has been proposed for this phenomenon, suggesting that a strong El Niño event in 1982/83 resulted in a failure of their main prey, market squid (Doryteuthis opalescens), which lead to their departure. However, we argue that previously underestimated impacts from fishery by-catch and other anthropogenic effects may have actually been the primary driver. Information from diverse sources show that from the 1950s to 1980s, pilot whales were subject to extensive by-catches in purse-seine nets, lampara nets, and oceanic driftnets, as well as intentional shooting by fishermen, and live-captures for the aquarium industry. As a result, dozens of animals may have been removed in some years. From 1952 to 2014, we have documented no less than 232 individuals removed from southern California, with \u3e52% through known anthropogenic factors. If these removals primarily affected the Catalina Island ‘residents’, they would have had a severe impact on that population. We conclude that human interactions of various types almost certainly played an important, and previously unrecognized, role in the disappearance of short-finned pilot whales from southern California waters
Late Quaternary Chorus Frog (Pseudacris) from the Channel Islands, California
Full text linkAbstract.-Fossil and subfossil remains of the vertebrate faunas from the northern Channel Islands, southern California, have been studied for many decades. Continued interest has focused on skeletal remains of birds, rodents, and mammoths from archaeological and paleontological localities, but considerably less attention has been placed on the detailed description of the herpetofauna (salamanders, anurans [frogs and toads], lizards, and snakes) on the Channel Islands. We present descriptions of an ilium of an anuran from Santa Rosa Island (Larramendy North; radiocarbon dating at least 13,393 calibrated years ago) and two tibiofibulae San Miguel Island (Daisy Cave) dating from earliest and middle late Holocene layers. We identify the fossil ilium as Pseudacris sp. (chorus frog): 1) it is the lowest level that skeletal morphology permits us to attempt, 2) realizing that it appears morphologically closest to P. regilla, and 3) yet realizing that not all species of Pseudacris and Hyla have been directly compared or are understood. The extant amphibian fauna on these islands is depauperate. The remains presented here represent the first description of a fossil anuran from the northern Channel Islands. It is now understood that a chorus frog lived on glacial-age Santa Rosae Island, yet it is not understood when its distribution was reduced to just the present two largest islands, Santa Rosa and Santa Cruz
