Shallow-Water Marine Climates and Molluscan Provinces

Hall, Clarence A.

doi:10.2307/1933835

Cited by 114 publications

(84 citation statements)

References 12 publications

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“…Instead, Hall (1964) suggested that the number of consecutive days in summer when shallow water temperatures are warm enough for spawning and larval activity is critical. Bernard et al (1991) found a strong positive correlation between mean annual surface temperatures and the number of intertidal bivalve species in the northeast Pacific.…”

Section: Molluscan Zonesmentioning

confidence: 99%

Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years

Dyke¹,

Dale²,

McNeely³

2007

gpq

116

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ABSTRACTDated mollusc collections are classified in assemblages to map paleo-faunistic zones. Hiatella arctica and Mya truncata account for almost half the records and comprise a restricted arctic assemblage. Arctic assemblages comprise 70% and arctic-dominated assemblages 80% of the database. Fifteen species dominate but 170 taxa are recorded. At last glacial maximum, the arctic zone extended from the Arctic Ocean to the Grand Banks. The boreal zone in the western Atlantic was compressed. The subarctic zone, which today dominates eastern Canada, was small. The boreal zone was extensive in the eastern Pacific where subarctic and arctic zones were compressed. Zones shifted northward during deglaciation and the arctic zone diversified when Bering Strait submerged 10.5-10.3 ka BP. Western Arctic molluscs during Younger Dryas time indicate shallow waters warmer than present. Major North Atlantic currents were established 9.5-9.0 ka BP. The subarctic zone extended to the head of Baffin Bay and a boreal zone became established in West Greenland 9-8 ka BP, with intensive changes about 8.5 ka BP. We relate the latter to the reduction of Mackenzie River discharge and in sea ice export to the North Atlantic as Laurentide ice withdrew from Mackenzie headwaters. The extended subarctic zone in Baffin Bay persisted until 3 ka BP and then retreated about 1000 km on the Canadian side. Boreal-subarctic molluscs in the Gulf of St. Lawrence before 9.5 ka BP derived from the glacial refugium. High boreal-subarctic molluscs farther north probably migrated from Europe. We postulate that the Labrador Current acts as a one-way valve for mollusc migrations at glacial-interglacial scales.

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Section: Molluscan Zonesmentioning

confidence: 99%

Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years

Dyke¹,

Dale²,

McNeely³

2007

gpq

116

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“…Provincial boundaries are located where waters of different major water masses or water types, conditioned in different climatic zones or representing mixtures of waters drawn from other distinctive sources, and distributed by currents, meet along the shelf (for example Dall 1921, Schenck & Keen 1936, Hall 1964, Valentine 1966, Gaylord & Gaines 2000. Previous studies have shown that provincial boundaries, formed by clusters of species-range endpoints, influence many aspects of northeastern Pacific molluscan biogeography (Roy et al 1994(Roy et al , 1998, and the finding that the geographic ranges of carnivores and non-carnivores are different and vary regionally raises the possibility that they are associated with similar features.…”

Section: Zonal Controlsmentioning

confidence: 99%

Carnivore/non-carnivore ratios in northeastern Pacific marine gastropods

Valentine¹,

Roy²,

Jablonski³

2002

Mar. Ecol. Prog. Ser.

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For 2321 species of shelled gastropods of the northeastern Pacific, the ratio of carnivorous to non-carnivorous species (C/NC ratio), computed for each degree of latitude, reveals striking spatial changes, with tropical and arctic areas characterized by high values and with the midlatitudes having the lowest ratios. This latitudinal trend is markedly different from trends for terrestrial clades. The zonal variation in C/NC ratios within bins is largely due to differences in geographic ranges of the groups; for example, tropical carnivorous species range farther than non-carnivorous ones, thus overlapping them in more latitudinal bins. Differences in the distribution and diversity of carnivorous and non-carnivorous species may arise from a number of sources, including variability of primary production in the tropical eastern Pacific, patchiness of substrates to which non-carnivores are adapted, narrow dietary specializations of tropical carnivores, and higher provinciality found in extratropical regions. KEY WORDS: Trophic ratios · Latitudinal diversity trends · Provinciality · Variable productivity Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 228: [153][154][155][156][157][158][159][160][161][162][163] 2002 show that the ratio varies with climate and bathymetry. We also show that differences in the geographic ranges of carnivorous and non-carnivorous species within climatic zones play an important role in determining the regional variations. Note that because few carnivorous gastropods prey exclusively on other gastropods (e.g. Taylor & Taylor 1977), we are not dealing with predator/prey ratios as analyzed in community food webs and subwebs. Thus the energetic constraints imposed within trophic pyramids do not apply (see also Gaston et al. 1992. Instead, we are interested in the partitioning of diversity between primary and higher-level consumers for a major clade along a latitudinal gradient; these patterns of feeding-type ratios have evolutionary implications and potential ecological consequences of their own. MATERIALS AND METHODSWe analyzed the diversity patterns of carnivorous and non-carnivorous species of shell-bearing marine gastropods (N = 2321 species) recorded on the continental shelf (above 200 m in depth) along the northeastern Pacific margin, from the southern edge of the Panamic province (Paita, Peru, 5°S) to the Arctic Ocean (off Point Barrow, Alaska, 72°N). Our distributional data consist of northern and southern range endpoints of individual species, and we assume that each species occurs continuously between those range endpoints (see Roy et al. 1998). A few clades were excluded because shells are absent or flimsy, so that they are likely to be poorly and unevenly represented in collections (such as most euthyneuran clades), or because they are so poorly understood taxonomically that their distributional records are untrustworthy (such as pyramidellids). We define as non-carnivores species that are browsers on marine plants, graze...

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“…These two coastline stretches are unique in having the widest temperature range. Each contains signi cant provincial boundaries (Hall, 1964;Valentine, 1966). The in uence of the large temperature range on parasite distributional pattern potentially minimizes the possibility that correlations with contaminants can be identi ed.…”

Section: Accepted Manuscriptmentioning

confidence: 99%