Data from: Bay-scale patterns in the distribution, aggregation and spatial variability of larvae of benthic invertebrates

• Main Authors: Daigle, Remi M., Metaxas, Anna, deYoung, Brad, Daigle, RM
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2015
• Subjects: spatial variability; Neopanopeus sayi; Electra pilosa; Carcinus maenas; Canadian Healthy Oceans Network; August 11-12 2008; Summer; Crepidula spp; Membranipora membranacea; Other Gastropods; Bryozoans; August 2-4 2009; Astyris lunata; benthic invertebrates; Diaphana minuta; larval dispersal; Bittiolum alternatum; Modiolus modiolus; Anomia simplex; decapods; August 7-8 2008; Spatial patchiness; Margarites spp; Larval aggregation; Crangon septemspinosa; gastropods; Other Bivalve; Population connectivity; Larval behaviour; Mytilus spp; Holocene; Cancer irroratus; Arrhoges occidentalis
• Online Access: https://doi.org/10.5061/dryad.fh505

This study aimed to investigate mechanisms of pattern formation in the larval distributions of benthic invertebrates by relating the spatial and temporal variability in the larval distributions to that in physical and biological variables, such as temperature, salinity, fluorescence and current velocity. Larvae were sampled at 11 sites on 7-8, and 11-12 Aug 2008 and at 16 sites on Aug 2-4, 2009, with a 200-μm plankton ring net (0.75-m diameter) towed for 5 min at 3 m and 12 m depth (in and below the mixed layer, respectively) in St. George's Bay, Nova Scotia, Canada. In 2009, density, temperature, salinity, and fluorescence were measured with a CTD cast at each station, and currents were quantified with an ADCP moored at 5 locations throughout the bay. In 2008, we only measured temperature. Gastropod, bivalve and, to a lesser extent, bryozoan larvae had very similar spatial distributions, but the distribution of decapod larvae followed a different pattern. These findings suggest that taxonomic groups that have functionally (i.e. swimming ability) similar larvae (e.g. bivalves and gastropods) also show similar dispersion properties (distribution and spatial variability), while the opposite is true for groups with functionally dissimilar larvae (e.g. bivalves and decapods). We also found that larval distributions of all taxa were significantly aggregated, although the degree of aggregation varied among taxa. Using an aggregation-diffusion model, we demonstrated that horizontal swimming was not an effective means of forming aggregations even at modest levels of diffusion. We hypothesize that patterns in observed horizontal distribution at this scale (< 40 km) are determined during the larval phase, and that the primary mechanism for pattern formation is larval interaction with physical oceanographic structures (e.g. stratification and tidal currents). Spatial distribution of Meroplanktonic larvae. A Canadian Healthy Oceans Network Population Connectivity project, PC-06 Larval abundance (count m-3) was sampled ...