Zoobenthic community establishment and habitat complexity-the importance of seagrass shoot-density, morphology and physical disturbance for faunal recruitment

Abstract

Seagrass meadows are among the most diverse coastal ecosystems in the Baltic Sea. There is, however, an apparent lack of quantitative data on functional aspects of these systems, such as plant-animal interactions. We tested the importance of seagrass density and morphology for benthic infaunal recruitment in a 2 mo (June/July 1997) field-experiment with both bare and vegetated (3 densities of artificial Ruppia maritima and Zostera marina) colonization trays with azoic sediment. These artificial seagrass patches were placed at 3 m depth in an unvegetated area of a sandy bottom seagrass site on the Åland Islands, northern Baltic Sea. Faunal succession was followed by SCUBAdiving and core sampling with 10 to 20 d intervals. The data showed strong effects of seagrass complexity and wind disturbance on (1) physical processes such as accumulation of drifting algae, particle trapping and sediment binding, (2) development of community parameters (abundance, species richness, diversity) and (3) species-specific colonization patterns. Our data further demonstrated the importance of post-settlement events for distribution of juvenile macrofauna (e.g. resuspension or transport by means of drifting algae), and showed negative and positive effects of wind-mediated disturbance in low-and high-complexity habitats, respectively. It is concluded that wind disturbance may act as a mechanism creating and maintaining high animal diversity in seagrass meadows.

How do harpacticoid copepods colonize detrital seagrass leaves?

“…In conclusion, our study is congruent with Bostrom and Bonsdorff (2000), whom stated that structurally complex plant assemblages (like macrophytodetritus) may trap or attract organisms more efficiently than structurally simple leaf canopies or bare sediments. Structural complexity and dispersion drivers, such as hydrodynamics (i.e.…”

Classifying Ecological Quality and Integrity of Estuaries

“…As a function of complex biogeochemical processes (Harris, 1999;Hansen et al, 2000;Eyre and Ferguson, 2002), seagrass meadows are extremely productive systems, which exhibit high biodiversity, and support complex food webs, constituting a habitat refuge for a number of organisms (Orth, 1992;Boström and Bonsdorff, 2000;Borum et al, 2005). Changes in seagrass areas are often a symptom of major changes in environmental characteristics, and therefore constitute an important indicator for assessing the state of the environment.…”

Polyplacophora (Mollusca) from reef ecosystems and associations with macroalgae on the Coast of Alagoas, Northeastern Brazil

“…Coralline algae had a higher rate of sediment retention by a stem, which benefits the associated invertebrate fauna by decreasing the negative effects of the physical stress of desiccation, reducing the mortality rate due to predation, increasing available space for the establishment of new larvae, refuge for many invertebrates that inhabit their fronds and also use them as food (BOSTRÖM & BONSDORFF 2000, KELAHER 2002. In the present study all chitons species, both adults and juveniles, which were found on the three phytals demonstrated a preference for the winter periods, between May and September.…”