The distribution, abundance and seasonality of pelagic marine invertebrate larvae in the maritime Antarctic

• Main Authors: Stanwell-Smith, D, Peck, LS, Clarke, A, Murray, AWA, Todd, Christopher David
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1999
• Subjects: larva; Antarctic; diversity; abundance; seasonality; marine invertebrate; SUBLITTORAL EPIFAUNAL COMMUNITIES; ICE-FOOT ZONE; BENTHIC INVERTEBRATES; SIGNY ISLAND; MCMURDO SOUND; SEA-ICE; ECOLOGY; LIFE; HISTORY; FERTILIZATION; Arctic; McMurdo Sound; Signy Island; Antarc*; Antarctica; Sea ice
• Online Access: https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-distribution-abundance-and-seasonality-of-pelagic-marine-invertebrate-larvae-in-the-maritime-antarctic(eee3f0ad-006c-4dfe-9404-b07abae25cf4).html; http://www.scopus.com/inward/record.url?scp=0033611662&partnerID=8YFLogxK

survey of pelagic larvae was undertaken between November 1992 and February 1995 at Signy Island, Antarctica (60 degrees 43' S, 45 degrees 36' W). A diver-towed net and hand-held plankton pump were used at five sites of varying depths (6-30 m) and benthic substrata, in a combination of monthly and fortnightly samples. Overall larval ecological diversity was much higher than expected, with 131 morphologically distinct larval forms collected, apparently representing most of the benthic phyla present. The species richness observed is comparable with levels recorded at temperate latitudes, and higher than Arctic data and the implications for Thorson's rule (the inferred dine of reduced pelagic larval diversity towards high latitudes) is discussed. Larval abundances were low (mean 2.6 individuals per m(3)), which were two to six orders of magnitude lower than peaks in comparable data from temperate and tropical zones. We suggest that the low abundances recorded are a reflection of both slow developmental rates and a high dilution of larvae, reducing synchrony and spreading larvae over larger distances. Three seasonal periods, during which different larval types occur, have been identified. Summer, late summer and winter spawning strategies were discernible, and in some groups larvae occurred throughout the year.