Patterns of abundance were documented for 17 species of fish in the lagoon at the mouth of San Mateo Creek, northern San Diego County, California from occasional observations (1974-1997) and multiple samples per year (1998-2008). Fish populations varied with Mediterranean climate patterns of rainfall, stream flow and consequent breaching of the lagoon to the ocean through the barrier sand berm. Two near-record rainfall seasons occurred during this period; the 1997-1998 El Niño due to southern storms and the 2004-2005 winter wet season of more usual storms from the north and northwest. The lagoon stabilized as fresh to brackish in the dry season and for multiple years during successive drier winters. Closed conditions benefitted the native, federally endangered southern tidewater goby, Eucyclogobius kristinae, but were less suitable for other native estuarine species more common in wetter years. Wet year flows also reduced non-native freshwater species; some thrived and increased predation pressure on the southern tidewater goby. Historically these exotics were absent and two additional native species were present, partially armored threespine stickleback, Gasterosteus aculeatus, and the federally endangered southern steelhead, Oncorhynchus mykiss. Restoring and maintaining a full suite of native species will require a combination of 1) habitat maintenance and restoration, 2) control or management of non-native species, and 3) reintroduction of some native fishes and amphibians.

There 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 >52% 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.

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 Santarosae Island, yet it is not understood when its distribution was reduced to just the present two largest islands, Santa Rosa and Santa Cruz.

A 14-month study was conducted of the polychaetous annelids present on attached wooden blocks at nine stations in Los Angeles Harbor in 2013-2014. The results were compared to a similar study conducted at the same stations in 1950-1951. The primary objective in both studies was to determine the location and occurrence of marine borers in the harbor. Since fouling organisms, including polychaetes, attached to the wooden blocks, it also provided an opportunity to study the polychaetes that settled on the blocks. The number of polychaete species in these two studies increased from 22 to 71. The serpulid Hydroides elegans was a dominate species in both studies but the pollution indicator Capitella capitata, common in the earlier study, was rare in the recent study. There was a seasonal occurrence in both the number of species and specimens with highs in the warmer months and lows from December through March in both studies. Many environmental changes have occurred in the Los Angeles Harbor complex over the past 63 years. New harbor piers constructed that extend into the Outer Harbor, channels have been dredged deeper and pollution abatement programs initiated. The water quality has been improved especially in the Inner Harbor as a result of these changes where the dissolved oxygen in the water was low or absent in 1950-1951 but higher (over 6.0 mg/L) in 2013-2014. This study is unusual since long-term, seasonal comparisons of marine invertebrate populations are uncommon.