Copepod populations during the spring bloom in an Alaskan subarctic embayment

Coyle, Kenneth O.; Paul, A. J.; Ziemann, David A.

doi:10.1093/plankt/12.4.759

Cited by 36 publications

(41 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, 3 copepod species were consistently more abundant only at the on-shelf stations: Calanus marshallae, Pseudocalanus mimus, and Acartia longiremis. We know that these species dominate shelf waters off Newport, Oregon (Peterson & Miller 1975) as well as coastal waters to the north; Vancouver Island (Mackas et al 2001), Gulf of Alaska (Coyle et al 1990), and the Bering Sea (Johnson & Brinton 1963). Thus, these 3 species are good indicators of the presence of Gulf of Alaska coastal water on the Oregon shelf.…”

Section: Discussionmentioning

confidence: 99%

Onshore-offshore variations in copepod community structure off the Oregon coast during the summer upwelling season

Morgan¹,

Peterson²,

Emmett³

2003

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

During the summer of 1994, 1996, and 1997, we conducted hydrographic and plankton surveys of the upper 70 m in the nearshore, the continental shelf, and off-shelf oceanic waters off Oregon, USA. Copepod densities and biomass were estimated along 4 transects from each cruise. The on-shelf copepod biomass was 2.8 times greater than off-shelf biomass. Nonmetric multidimensional scaling identified an on-shelf and an off-shelf copepod community. The change in community composition usually occurred at or slightly offshore of the continental shelf break, defined here as 180 m water depth. Indicator-species analysis identified the subarctic neritic species, Calanus marshallae, Pseudocalanus mimus, and Acartia longiremis, as good indicators of continental shelf waters. 'Warm water' species Mesocalanus tenuicornis, Calocalanus styliremis, Clausocalanus spp., and Ctenocalanus vanus were indicators of off-shelf waters. The copepod communities off the coast of Oregon during the summer upwelling season reflect the origins of the dominating currents within each habitat. The coastal copepod community is subarctic neritic in origin, consistent with southward coastal flows. The offshore copepod community is a mixture of species with origins in the Transition Zone as well as species that are typical of the coastal region of the California Current off central and southern California. We speculate that the central and southern California Current species are present in offshore waters of Oregon in summer because they are transported north with the Davidson Current in winter but, with the initiation of the upwelling season in spring, they are transported into offshore waters where they establish viable populations. KEY WORDS: Community structure · Copepod distributions · Nonmetric multidimensional scaling · OregonResale or republication not permitted without written consent of the publisher

show abstract

Section: Discussionmentioning

confidence: 99%

Onshore-offshore variations in copepod community structure off the Oregon coast during the summer upwelling season

Morgan¹,

Peterson²,

Emmett³

2003

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…3, 7). Grazing by herbivorous zooplankton, whose populations had increased rapidly in response to the primary bloom (Coyle and Paul 1990), nearly balanced the increased production. Between and following the secondary blooms, biomass levels were generally quite low, like those observed during the pre-bloom period.…”

Section: Secondary Bloomsmentioning

confidence: 98%

Interannual variability in the spring phytoplankton bloom in Auke Bay, Alaska

et al. 1991

View full text Add to dashboard Cite

Abstract. Data on phytoplankton primary production, biomass, and species composition were collected during a 5 yr (1985)(1986)(1987)(1988)(1989)) study of Auke Bay, Alaska. The data were used to examine the interannual differences in the timing, duration, and magnitude of the spring phytoplankton blooms during each year and to relate these differences to interannual variations in weather patterns. Within any given year, a pre-bloom phase was characterized by low available light, low rates of primary production, low biomass, and predominantly small (< 10 #m) diatoms. During the primary bloom, integrated production rates rose to 4 to 4.5 g C m -2 d -1, and integrated biomass levels reached 415 to 972 mg chlorophyll m -2. Primary blooms were usually dominated by large diatoms (Thalassiosira spp.), and in a single year (1989) by Chaetoceros spp. The primary blooms terminated upon nutrient depletion in the euphotic zone. Secondary blooms, triggered by nutrient resupply from below, occurred sporadically after the primary bloom and accounted for 4 to 31% of total spring production. The date of initiation and the duration of the primary bloom varied little from year to year (standard deviation 3 and 5 d, respectively). Seasonal production rates and biomass levels varied interannually by a factor of 2 to 3. In contrast, intra-annual variations of more than an order of magnitude, especially in biomass, occurred over periods as short as 10 d. These large variations over short time periods indicate the importance of synchronous timing between spring blooms and the production of larval fish and shellfish, which depend on an appropriate and adequate food supply for growth and survival. Parameters describing primary production (e.g. peak daily production, mean daily production, and total production during the primary bloom and the entire season) exhibited little interannual variation (coefficient of variation, CV = 10 to 19%), but a large degree of intra-annual variation (CV= 77 to 116%). Similarly, interannual variations in biomass (peak chlorophyll, mean chlorophyll) were also lower (CV=20 to 33%) than intra-annual variations (CV=85 to 120%).

show abstract

“…Throughout the North Pacific, Metridia pacifica is the most common species within the genus (Brodsky 1967), but the larger M. okhotensis is also relatively common, especially in deep, semi-enclosed systems such as the Okhotsk Sea (Brodsky 1967, 1977, Shebanova 1997, the deep Bering Sea (Ozaki et al 2001), and fjords in the north-eastern Pacific (Gardner & Szabo 1982), including Alaskan coastal embayments (Coyle et al 1990, Cooney et al 2001). In the Gulf of Alaska, where sampling has been conducted consistently during night-time, Metridia species rank second in larger-bodied copepod abundance after Neocalanus species during spring and early summer, but typically rank first for the remainder of the year (Coyle & Pinchuk 2003).…”

Section: Introductionmentioning

confidence: 99%