Streamflow and La Niña event relationships in the ENSO-streamflow core areas

EXTRACT (SEE PDF FOR FULL ABSTRACT): The high index phase of the Southern Oscillation (SO), La Niña, has not been given as much attention as its counterpart, the low index phase of the SO, El Niño. One reason may be related to the fact that many similarities exist among El Niño events but not among La Niña events. ... In this study, we focus on the influences of La Niña phenomena on streamflow anomalies ... to explore the SO-related signal over the United States.

Relationships between ENSO events and San Francisco rainfall, 1949-1991

As California entered its sixth consecutive year of drought, the onset of a positive sea surface temperature anomaly in the equatorial Pacific and other indicators of a developing ENSO event were observed. This brought the following question from the media, water officials, and the public: What effect will El Niño have on the current rainfall season in general and on the intraseasonal distribution of rain in particular? To answer the question, the historical San Francisco rainfall record was examined in relationship to previous ENSO events.

Feeding on protists and particulates by the leptocephali of the worm eels Myrophis spp. (Teleostei: Anguilliformes: Ophichthidae), and the potential energy contribution of large aloricate protozoa

The food sources of the leptocephali of the teleostean superorder Elopomorpha have been controversial, yet observations on the leptocephali of the worm eels, Myrophis spp. (family Ophichthidae) collected in the northern Gulf of Mexico indicate active, not passive, feeding. Leptocephali had protists in their alimentary canals. Estimates of the physiological energetics of worm eels indicate that large aloricate protozoa including ciliates could provide substantial energy to these leptocephali toward the end of the premetamorphic and metamorphic stages, given the low energy requirements of metamorphosing leptocephali. Global ocean warming will likely force a shift in oceanic food webs; a shift away from large protozoa toward smaller protists is possible. Such a disruption of the oceanic food webs could further compromise the survival of leptocephali.

A GIS analysis of coastal development and trends in bottlenose dolphin strandings in Charleston, SC: implications for coastal marine spatial planning

Bottlenose dolphins (Tursiops truncatus) inhabit estuarine waters near Charleston, South Carolina (SC) feeding, nursing and socializing. While in these waters, dolphins are exposed to multiple direct and indirect threats such as anthropogenic impacts (egs. harassment with boat traffic and entanglements in fishing gear) and environmental degradation. Bottlenose dolphins are protected under the Marine Mammal Protection Act of 1972. Over the years, the percentage of strandings in the estuaries has increased in South Carolina and, specifically, recent stranding data shows an increase in strandings occurring in Charleston, SC near areas of residential development. During the same timeframe, Charleston experienced a shift in human population towards the coastline. These two trends, rise in estuarine dolphin strandings and shift in human population, have raised questions on whether the increase in strandings is a result of more detectable strandings being reported, or a true increase in stranding events. Using GIS, the trends in strandings were compared to residential growth, boat permits, fishing permits, and dock permits in Charleston County from 1994-2009. A simple linear regression analysis was performed to determine if there were any significant relationships between strandings, boat permits, commercial fishing permits, and crabpot permits. The results of this analysis show the stranding trend moves toward Charleston Harbor and adjacent rivers over time which suggests the increase in strandings is related to the strandings becoming more detectable. The statistical analysis shows that the factors that cause human interaction strandings such as boats, commercial fishing, and crabpot line entanglements are not significantly related to strandings further supporting the hypothesis that the increase in strandings are due to increased observations on the water as human coastal population increases and are not a natural phenomenon. This study has local and potentially regional marine spatial planning implications to protect coastal natural resources, such as the bottlenose dolphin, while balancing coastal development.

Swimming depth, ambient water temperature preference, and feeding frequency of young Pacific bluefin tuna (Thunnus orientalis) determined with archival tags

We investigated the migration and behavior of young Pacific Bluefin tuna (Thunnus orientalis) using archival tags. The archival tag measures environmental variables, records them in its memory, and estimates daily geographical locations based on measured light levels. Of 166 archival tags implanted in Pacific bluefin tuna that were released at the northeastern end of the East China Sea from 1995 to 1997, 30 tags were recovered, including one from a fish that migrated across the Pacific. This article describes swimming depth, ambient water temperature, and feeding frequency of young Pacific bluefin tuna based on retrieved data. Tag performance, effect of the tag on the fish, and horizontal movements of the species are described in another paper. Young Pacific bluefin tuna swim mainly in the mixed layer, usually near the sea surface, and swim in deeper water in daytime than at nighttime. They also exhibit a pattern of depth changes, corresponding to sunrise and sunset, apparently to avoid a specific low light level. The archival tags recorded temperature changes in viscera that appear to be caused by feeding, and those changes indicate that young Pacific bluefin tuna commonly feed at dawn and in the daytime, but rarely at dusk or at night. Water temperature restricts their distribution, as indicated by changes in their vertical distribution with the seasonal change in depth of the thermocline and by the fact that their horizontal distribution is in most cases confined to water in the temperature range of 14−20°C.

Opportunistic feeding of longhorn sculpin (Myoxocephalus octodecemspinosus): Are scallop fishery discards an important food subsidy for scavengers on Georges Bank?

There has been much recent interest in the effects of fishing on habitat and non-target species, as well as in protecting certain areas of the seabed from these effects (e.g. Jennings and Kaiser, 1998; Benaka, 1999; Langton and Auster, 1999; Kaiser and de Groot, 2000). As part of an effort to determine the effectiveness of marine closed areas in promoting recovery of commercial species (e.g. haddock, Melanogrammus aegelfinus; sea scallops, Placopecten magellanicus; yellowtail flounder, Limanda ferruginea; cod, Gadus morhua), nontarget species, and habitat, a multidisciplinary research cruise was conducted by the Northeast Fisheries Science Center (NEFSC), National Marine Fisheries Service. The cruise was conducted in closed area II (CA-II) of the eastern portion of Georges Bank during 19–29 June 2000 (Fig. 1). The area has historically produced high landings of scallops but was closed in 1994 principally for groundfish recovery (Fogarty and Murawski, 1998). The southern portion of the area was reopened to scallop fishing from 15 June to 12 November 1999, and again from 15 June to 15 August 2000. While conducting our planned sampling, we observed scallop viscera (the noncalcareous remains from scallops that have been shucked by commercial fishermen at sea) in the stomachs of several fish species at some of these locations, namely little skate (Raja erinacea), winter skate (R. ocellata), red hake (Urophycis chuss), and longhorn sculpin (Myoxocephalus octodecemspinosus). We examined the stomach contents of a known scavenger, the longhorn sculpin, to evaluate and document the extent of this phenomenon.

Biology and feeding behavior of Orbinia johnsoni

Orbinia johnsoni were studied from a small sandy beach near Mussel Pt., Pacific Grove, California, where they are most abundant at low tide levels in fine sand. They were found to have a mean length of 190 mm. The orbiniids were found with their guts the fullest during incoming to high tides. It is plausible that this is when they are feeding. It takes about 3 to 3.5 hours for food to travel through the length fo the gut. The orbiniids eat 93 percent sand and seven percent organic detritus. Special note should be taken that some food selectivity appears to be involved and that high percentages of organic matter in the feces are found in worms collected during low, outgoing tides. Evidence suggests that the worms are bottom feeders, not coming to the surface to feed.

Relationships between climate and atmospheric circulation in the Sonoran Desert region

The goal of this research is to identify key features of atmospheric circulation that influence winter climate variability in the Sonoran Desert region. This relationship between winter climate and atmospheric circulation is investigated through the use of indices, which describe the principal features of circulation patterns.

Food and feeding habits of Schizothorax longipinnis Heckel from River Jhelum, Kashmir

Food and feeding habits of Schizothorax longipinnis inhabiting river Jhelum were studied by observing the gut contents of 225 fishes. The species is found to be illiophagic and herbivore in nature, chiefly feeding on decayed organic matter (54.2%), sand and mud (25.7%), food of plant and animal origin (20.1%). Correlation between food intake and various size groups for different seasons have been discussed in details.

Studies on the feeding biology of an airbreathing fish Heteropneustes fossilis (Bloch)

The food and feeding habits of an air-breathing fish, Heteropneustes fossilis were studied from an eutrophic lake, Hussainsagar, Hyderabad, (Andhra Pradesh, India), during 1981-1983. The major preferred items of food were insect larvae, insects, ostracods, plant material and gastropods. Due to the mixed feeding habits of both plant and animal matter, this species is considered as an omnivorous feeder. Bryozoans were recorded for the first time in the diet of H. fossilis.

Morphometry, length-weight relationship and food and feeding habits of Otolithoides biauritus (Cantor, 1850) of Bombay waters

Thirteen morphometric and seven meristic characters, length-weight relationship and food and feeding habits of Otolithoides biauritus of Bombay coast (Maharashtra, India) were studied. Compared morphometric characters revealed positive allometric growth and high correlation ("r" ranging 0.898 - 0.996) between each other. Meristic characters were observed to be B sub(vii), D sub(1) 8-10, D sub(2) 27-31, P 17-20, V 5-7 and 7-10. Number of gill rackers on the first left gill arch ranged from 15 to 19. Length-weight relationship for both sexes together worked out to be W = 0.026, L super(2.646). The species is a predator, feeding mainly on motile Acetes, small fish and Loligo in order of preference.

Food and feeding habits of Megalaspis cordyla (Linnaeus, 1758) along the northwest coast of India

Megalaspis cordyla as one of the shoaling commercially important pelagic fish in the Northwest coast of India. The study on food and feeding habits of this fish revealed that it is predominantly a carnivorous species feeding primarily on sergestied shrimps like Acetes indicus and small fishes such as Stolephorus species. In addition it feeds on juveniles of Trichiurus, Apogon, Coilia, Sardinella, Nemipterus, Thryssa, and sciaenids. The food of M. cordyla also comprises the young ones of molluscs, especially Loligo and Sepia and occasionally ostracods. The choice food is Acetes indicus.