23 research outputs found
Fisheries and Marine Resources of Hawaii and the U.S.-associated Pacific Islands: An Introduction
The fisheries of Hawaii and other U.S.-associated islands in the Pacific Ocean are characterized by high diversity, both in the species exploited and the human cultures that exploit them. The commercial sector has undergone rapid growth in recent years, but recreational and subsistence sectors remain important. Information on these fisheries is generally not available in published form. This paper presents an overview and introduction to a volume of papers describing fisheries in the region, with the goal of making the information available to scientists and the general public. A great deal remains to be learned about the dynamics of these fisheries as well as the associated issues in biological research, fisheries management, and environmental protection
Dynamics of temperature and chlorophyll structures above a seamount: An oceanic experiment
Three hydrographic surveys comprised of densely spaced XBT and CTD stations were conducted over Minami-kasuga Seamount, in the northwest Pacific (21°36′N, 143°38′E). A cold dome, similar to a Taylor column, was observed above the seamount top during the first survey. Uplifted isotherms penetrated to the lower euphotic zone and were associated with higher chlorophyll concentrations. Vertical displacement of uplifted isotherms decayed with elevation above the seamount, so that both temperature and chlorophyll anomalies were undetectable at depths less than 80 m. Relatively high chlorophyll concentrations in a layer from 80 m to 100m depth formed a distinctive deep chlorophyll maximum (DCM) which was less well defined away from the seamount. Calculations based on the observed chlorophyll increase and on estimated phytoplankton growth rate suggested a minimal residence time of the cold dome on the order of several days. Zooplankton densities were also higher over the seamount top, both within and above the cold dome. No cold dome, chlorophyll increase, or high zooplankton biomass were detected above the seamount on the second and third surveys, carried out 2 and 17 days later, respectively. Mixing and deflections of isotherms occurred within a boundary zone around the seamount slope during the first and third surveys.Our observations suggest that seamounts are a source of both biological and physical patchiness in the surrounding ocean as features developed above them are swept away. The importance of the seamount-generated experiment is discussed in relation to field studies of the DCM. Specifically, our observations suggest that a sharp chlorophyll maximum can be formed by enhanced in situ growth following a sub-surface upwelling event
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Environmental and Ecological Effects of Ocean Renewable Energy Development: A Current Synthesis
Marine renewable energy promises to assist in the effort to reduce
carbon emissions worldwide. As with any large-scale development in the marine
environment, however, it comes with uncertainty about potential environmental
impacts, most of which have not been adequately evaluated—in part because many of
the devices have yet to be deployed and tested. We review the nature of environmental
and, more specifically, ecological effects of the development of diverse types of marine
renewable energy—covering marine wind, wave, tidal, ocean current, and thermal
gradient—and discuss the current state of knowledge or uncertainty on how these
effects may be manifested. Many of the projected effects are common with other types
of development in the marine environment; for example, additional structures lead to
concerns for entanglement, habitat change, and community change. Other effects are
relatively unique to marine energy conversion, and specific to the type of energy being
harnessed, the individual device type, or the reduction in energy in marine systems.
While many potential impacts are unavoidable but measurable, we would argue it
is possible (and necessary) to minimize others through careful device development
and site selection; the scale of development, however, will lead to cumulative effects
that we must understand to avoid environmental impacts. Renewable energy
developers, regulators, scientists, engineers, and ocean stakeholders must work
together to achieve the common dual objectives of clean renewable energy and a
healthy marine environment
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Feeding ecology of pelagic larvae of English sole Parophrys vetulus and butter sole Isopsetta isolepis off the Oregon coast
The food habits of the 2 dominant larval pleuronectids off the Oregon coast - English sole Parophrys vetulus and butter sole Isopsetta isolepis - were analysed. Most specimens were collected during January-April 1971 and March-April 1973. As is typical of larval fishes, I. isolepis larvae ingested a variety of prey which changed with increasing fish size. Small larvae fed predominantly on tintinnids, invertebrate eggs, and nauplii, whereas large larvae consumed more copepodite and adult copepods. In contrast, the diet of P. vetuluslarvae is very specific; appendicularians (Oikopleura spp.) comprised 97% of the total number of food items consumed in 1973. Both P. vetulus larvae and appendicularians are most abundant during fall and winter when total zooplankton concentrations off Oregon are low. I. isolepis larvae are most abundant during spring when upwelling stimulates productivity. In 1971, seasonal abundance peaks of P. vetulus larvae and appendicularians did not coincide. During this year, larvae fed less on appendicularians than in 1973 (66% of the total number of food items), and more on other food sources such as tintinnids, invertebrate eggs, and nauplii. In 1971 more P. vetulus larvae had empty guts than in 1973; this observation suggests increased starvation. In addition, fewer large larvae were present in 1971, perhaps due to higher mortality rates. Hence, in contrast to I. isolepis larvae, P. vetulus larvae are dependent upon a specific prey; a mismatch of P. vetulus and appendicularian abundance peaks may result in significant food-related mortality
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Improving Seawater Pumping and Small Docks at the Hatfield Marine Science Center: A Planning Workshop - May 14, 2007 Hatfield Marine Science Center Newport, Oregon
The HMSC brought together three dozen scientists, engineers, educators, and facilities managers from throughout the Pacific Northwest for a day-long workshop on May 14, 2007 to assess and prioritize infrastructure improvement needs for seawater pumping and bay/ocean access in support of the HMSC’s research and education mission. Funded by a National Science Foundation institutional planning grant, the primary objectives of the workshop were to identify specific requirements and make the initial steps in designing new dock facilities that will allow a variety of activities beyond existing capabilities
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Environment and Resources of Seamounts in the North Pacific: Proceedings of a Workshop, March 21-23, 1984, Shimizu, Japan
Report that includes summaries of sessions and papers presented at a workshop on "Environment and Resources of Seamounts in the North Pacific," held March 21-23, 1984 at the Orido Community Center near the Far Seas Fisheries Research Laboratory and the Government Port Building in Shimizu, Japan
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Effects of volcanic ash and estuarine sediment on the early life history stages of the Pacific herring, Clupea harengus pallasi
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HMSC Master Plan 2007-2020
The purpose of the Hatfield Marine Science Center Master Plan is to provide a plan to guide future development to support the marine science research, education and outreach initiatives through fiscal year 2022
Populations of the Sternoptychid Fish Maurolicus muelleri on Seamounts in the Central North Pacific
The lightfish, Maurolicus muelleri (Gmelin), is a cosmopolitan
sternoptychid fish most abundant near continental shelf-slope breaks and rare
in the open ocean. Recent studies have documented dense populations on
seamounts of the South Atlantic and North Pacific. At Southeast Hancock
Seamount, a small guyot in the central North Pacific, M. muelleri populations
are mainly composed of juveniles. Seasonal length frequencies suggest that
recruitment at sizes greater than 20 mm standard length (SL) occurs principally
in spring and summer months, with growth over summer and fall coincident
with decreasing abundances. Mature fish in reproductive condition occur in
winter months but do not survive to the following spring; they also may be too
few at this small seamount to support annual recruitment. Potential sources of
additional recruitment include populations at several larger seamounts in the
southern Emperor group and also the large populations around Japan. Advection
of eggs and larvae in the Kuroshio Extension may provide recruits for
dependent populations at the seamounts. Mean current flow and satellite-tracked
drifters suggest a transit time of 100-200 days from the coast of Japan
to the region of the seamounts; estimates of age at length suggest that smaller
fish have similar ages at recruitment. Gill-raker counts, however, differ between
Japanese and seamount populations. We suggest that the southern Emperor
Seamount populations serve as the source for replenished annual recruitment to
the small population at Southeast Hancock Seamount
REPRODUCTION, EMBRYONIC ENERGETICS, AND THE MATERNAL-FETAL RELATIONSHIP IN THE VIVIPAROUS GENUS SEBASTES (PISCES: SCORPAENIDAE)
Volume: 167Start Page: 354End Page: 37