Resource limitation in marine soft sediments - differential effects of food and space in the association between the brittle-star Amphiura filiformis and the bivalve Mysella bidentata?
Josefson, A.B. (1998). Resource limitation in marine soft sediments - differential effects of food and space in the association between the brittle-star Amphiura filiformis and the bivalve Mysella bidentata?, in: Baden, S. et al. Recruitment, colonization, and physical-chemical forcing in marine biological systems: Proceedings of the 32nd European Marine Biology Symposium, held in Lysekil, Sweden, 16-22 August 1997. Developments in Hydrobiology, 132: pp. 297-305. https://dx.doi.org/10.1007/978-94-017-2864-5_24 In: Baden, S. et al. (1998). Recruitment, colonization, and physical-chemical forcing in marine biological systems: Proceedings of the 32nd European Marine Biology Symposium, held in Lysekil, Sweden, 16-22 August 1997. European Marine Biology Symposia, 32. Developments in Hydrobiology, 132. ISBN 978-0-7923-5273-0; e-ISBN 978-94-017-2864-5. IX, 380 pp. https://dx.doi.org/10.1007/978-94-017-2864-5, more In: European Marine Biology Symposia., more Related to:Josefson, A.B. (1998). Resource limitation in marine soft sediments - differential effects of food and space in the association between the brittle-star Amphiura filiformis and the bivalve Mysella bidentata? Hydrobiologia 375: 297-305. https://dx.doi.org/10.1023/A:1017077510168, more |
Keywords | Aquatic communities > Benthos Aquatic organisms > Heterotrophic organisms > Filter feeders Availability > Food availability Interspecific relationships Interspecific relationships > Competition Limiting factors Population dynamics Amphiura filiformis (O.F. Müller, 1776) [WoRMS]; Mysella bidentata (Montagu, 1803) [WoRMS] Marine/Coastal |
Abstract | While it may be a consensus that food is the major limiting factor for total macrofaunal standing stock in marine sediments below the euphothic zone, little is known about limiting resources on species level. This issue is addressed by analysing field population data of the facultative filter-feeding burrowing ophiuroid Amphiura filiformis and its coinhabitant, the bivalve Mysella bidentata in two gradients of pelagic productivity. In a temporal gradient, 1971–1994, with high productivity in the 80 s, abundance of Amphiura at 100 m depth showed logistic population growth (R 2 = 0.90, n = 33) with carrying capacity reached in 1986 (ca. 3000 ind m−2). Mysella abundance versus time was best modelled by an exponential increase, occurring mainly during the period when Amphiura had reached maximum density (1986–1994) (R 2 = 0.75, n = 18). Amphiura showed somatic growth during the ‘plateau period’ of similar magnitude as predicted from independent data from the Kattegat. These observations indicate that Amphiura not was food limited in the plateau period. In the spatial gradient, inferred from chlorophyll concentrations in the surface sediment at 60 sites bisecting the area of the Skagerrak-Kattegat pelagic front, where primary productivity is elevated, Amphiura reached maximum abundance at the same level as in the temporal gradient, while Mysella and total benthic biomass peaked in the area of highest phytoplankton input to the sediment (Josefson & Conley, 1997). High content of the plant pigments chlorophyll-a (Chl-a) and phaeopigments in Amphiura suggested ingestion of labile algal matter, and a tentative chlorophyll budget indicated that Amphiura metabolic demand could be accounted for by ingestion of relatively fresh algal derived matter if half-lives of total chlorophyll in Amphiura were on the order of 1/2–1 h. The results suggest that space may be a limited resource in some soft-sediment systems where filter-feeding is a dominating feeding mode, and input of fresh phytoplankton to the bottom is high i.e. where pelagic-benthic coupling is strong. |
|