Plankton and micronekton occupy the base and intermediate levels of oceanic food webs and are generally regarded as difficult to quantify. Gelatinous plankton are the most abundant functional group of macroplankton, yet they remain largely unstudied. What little is known of plankton communities has been largely deduced from plankton samplers, optical counters, nets, and towed cameras. We introduce here a survey methodology that used recreational scuba divers to evaluate pelagic community structure observed on popular “blackwater” dives. The most abundant organisms encountered were salps, siphonophores, and ctenophores. Over a 19-month period, environmental data were compared against nightly observed diversity to build a generalized additive model that accounted for 43% of the total observed deviation in biodiversity. The three most important predictors of pelagic diversity were water temperature, bathymetry, and El Niño–Southern Oscillation (ENSO) index.

During 2015–2016, a strong El Niño event, nicknamed the “Godzilla El Niño,” occurred in the Pacific Ocean. Using satellite imagery, in this article we assess impacts of this event on sea-surface temperature and chlorophyll-a concentrations in the southern Gulf of California. Daily images of sea-surface temperatures and chlorophyll-a were obtained by satellite from the Moderate Resolution Imaging Spectroradiometer for the period from January 2013 to December 2017. A circular area ≈ 46.8 km in diameter in the central part of the gulf was selected to evaluate monthly variation of both parameters. Hydrographic data generated during a research cruise in November 2016 were used to evaluate water mass distributions. Results revealed strong seasonal variability, with high chlorophyll-a concentrations recorded during winter and low values during summer. Contrary to predictions, the “Godzilla El Niño” event apparently did not have as large an impact on the phytoplankton biomass, expressed as chlorophyll-a, in this region in comparison to other areas and to previous strong El Niño events. This is likely related to gulf dynamics and to the mechanism of productivity enhancement, although further observations are required to confirm this theory. Results presented contribute to a better understanding of the highly productive and unique Gulf of California ecosystem.

Dramatically intensified economic development in the coastal areas of Zhejiang, China, has posed unprecedented challenges and pressures on the native coastal marine biota. Mugilids (Teleostei: Mugiliformes) are widely distributed across marine, brackish, and freshwater habitats in tropical, subtropical, and temperate regions of the world. In this study, DNA sequences of a consensus length of 611 nucleotides in mitochondrial Cytochrome c Oxidase subunit I (COI ) were used to identify 144 mugilid samples collected from various intertidal waters along the coast of Zhejiang in the East China Sea. A total of 35 distinctive COI haplotypes was scored. Results of neighbor-joining ( NJ) clustering clearly support classification of seven species, in agreement with morphological diagnosis: Planiliza affinis, Planiliza haematocheila, Planiliza sp. H, Planiliza subviridis, Crenimugil sp. A, Osteomugil cunnesius, and Mugil sp. C. Planiliza affinis was found to be the dominant mugilid in the coastal waters. This research provides critical scientific data for understanding the identity and abundance of mugilids and managing their fishery resources and habitats along the coast of Zhejiang.

Sexual recruitment allows corals to maintain their populations through time, reach new habitats, and repopulate areas after an environmental or anthropogenic disturbance. This study aimed to estimate spatiotemporal variation of sexual recruitment along two areas of the southwestern coast of the Gulf of California (Bahía de La Paz and Bahía de Loreto) considered to be suboptimal for coral development (strong seasonality and variability of sea-surface temperature, incidence of hurricanes, turbidity and nutrient concentration, and low Ωar). Recruitment data were compared to sea-surface temperatures and with recruitment data from other sites in the eastern Pacific that have less-stressful environments. Terracotta tiles were used as collectors of larval coral propagules; tiles were immersed for 3-month periods between August 2004 and September 2005. Higher recruitment was found during the warm season, and coral recruits were found at almost all sites, including a vessel grounding area. Recruitment was higher in Bahía de La Paz [12.80 ± 29.57 individuals (ind) m^-2 yr^-1] than in Bahía de Loreto (0.99 ± 1.49 ind m^-2 yr^-1). Coral recruits belonged to five coral genera in Bahía de La Paz, with Porites as the dominant genus (102 recruits), followed by Pocillopora (six), Psammocora (three), Pavona, and Tubastraea (one each). At Bahía de Loreto, recruits of two coral genera were recorded: Porites (four) and Psammocora (one). Despite being conducted in a highly stressful environment, this study reports the second-highest rate of Porites recruits in the eastern Pacific and the first instance of Psammocora recruits (four ind) in the area.

Clumps of the gooseneck barnacle Pollicipes elegans were found in the central Pacific on a rocky shore of Costa Rica. This species is known to be abundant in northern and southern latitudes of the eastern tropical Pacific. This study describes aspects of its demography and size structure, as well as habitat features in Costa Rica. The clumps were generally on vertical rocky substrates, with a negative slope and an average height of 1.70 m above the Lowest Astronomical Tide. Two cohorts were found on the rocky shore in 2014. An important decline of abundance and density of clumps was found between July and October of 2014. Additional clumps were found in September 2016. We present hypotheses about how this species became established in Costa Rica and why a decline of the clumps was observed.

In the eastern Pacific Ocean, whale sharks (Rhincodon typus) have mostly been studied off the Galápagos Islands, Ecuador, and Baja California, Mexico. Recently, satellite telemetry data revealed connectivity between whale sharks off the Galápagos Islands and Peru. Historic and some recent observations have reported rare occurrences of whale sharks in waters off northern Peru. However, no current detailed information on the occurrence of whale sharks in Peruvian waters has been published. In this study we compiled 27 records of whale sharks along the Peruvian coast as a first step to better understand their use of Peruvian waters. Northern Peru was identified as the main area of occurrence for whale sharks, and reports were more frequent during the austral summer (January to March) and spring (October to December). Moreover, presence of neonatal whale sharks reported in this study, in addition to that of previously satellite-tracked presumably pregnant females, suggests use of northern Peruvian waters as a pupping ground. Interactions occurred only with net fisheries and were evident in most (89%) of the records, but further studies should evaluate the extent of fisheries-shark interactions. As whale shark population numbers decline, effective conservation measures will require understanding of whale shark occurrences, and waters of northern Peru may play an important role in the species' biology and ecology. Systematic research is recommended to improve our understanding of habitat use of individuals present in Peruvian waters.

Photographs of a whale initially found alive in mangroves in Pohnpei, Federated States of Micronesia (FSM), in July 2016 document the first record of the genus Kogia in the Caroline Islands. With its small size and what can be seen of its dentition, it most closely resembles a dwarf sperm whale, Kogia sima, but the possibility of it being an immature pygmy sperm whale, K. breviceps, cannot be excluded. In addition, we report the first documented record of a short-finned pilot whale, Globicephala macrorhynchus for Pohnpei State, and the first confirmed records of killer whales, Orcinus orca, and false killer whales, Pseudorca crassidens, for the FSM and the Caroline Islands, respectively.

As human impacts on island ecosystems increase, so does the importance of understanding life histories of island plants for conservation. Yet, surprisingly little is known about reproductive ecology of many common island plant species. We experimentally investigated the breeding system and observed pollinators of the endemic Hawaiian vine Jacquemontia sandwicensis (Convolvulaceae), a common species in coastal strand habitat. To evaluate the breeding system, experiments involving natural and hand pollination treatments were performed in the field and with cultivated plants. To identify natural pollinators, flower-visiting insects were observed in three sites on the southeastern coast of O‘ahu. Jacquemontia sandwicensis is a self-compatible, hermaphroditic species with a flexible, mixed mating system. High levels of fruit set, seed set, and germinating seeds seem to depend on pollen being deposited on the stigma by an active pollinator rather than a passive vector (wind or autogamy). However, this species still produced some fruit and seeds even in the absence of manipulation, suggesting a limited degree of reproductive assurance when pollinators are absent or in low abundances. At the observed sites, this species was visited by a variety of mostly nonnative Hymenoptera (especially Apis mellifera and Lasioglossum spp.). The endangered native bee Hylaeus anthracinus also visited flowers, but at a much lower rate than the nonnative insects. Nonnative insects appear to be effective pollinators for J. sandwicensis and now play an important role as native pollinators decline.

The presence of large numbers of free-ranging feral cats (Felis catus) has raised concern in terms of both native species predation and potential disease transmission in Hawai‘i. A disease of particular concern is toxoplasmosis, caused by Toxoplasma gondii, a zoonotic protozoan parasite. We tested soil samples and cat fecal samples from cat colonies from an urban university campus and a natural, coastal ecosystem for T. gondii oocysts using standard molecular procedures. Soil and fecal samples were collected from cat colony sites at the University of Hawai‘i at Mnoa (UHM), and additional fecal samples were collected from cats trapped within Ka‘ena Point Natural Area Reserve (KPNAR). Toxoplasma gondii DNA was detected in 5% (3 of 60) of fecal samples from UHM, but no T. gondii DNA was detected from soil samples. At KPNAR, 22.2% (2 of 9) of fecal samples were positive for T. gondii DNA. Presence of T. gondii at the university study sites suggests that cat colonies may be a potential health hazard for landscaping personnel, students, staff, and visitors. Likewise, presence of T. gondii at KPNAR, and potentially other coastal habitat(s) for ground-nesting seabirds or marine mammals, also suggests a disease risk and should be considered when managing those areas. Toxoplasmosis is a growing concern to both people and wildlife, and further work is needed to determine pathways of transmission both within and between terrestrial and marine ecosystems of Hawai‘i.