Biology subjects

Totterman, S.

Publications and source records attributed to Totterman, S..

3 recordsLinked to original sources

bioRxiv2019

A \"feet digging\" swash zone sampling method for the sandy beach bivalve Donax deltoides (Bivalvia: Donacidae)

A \"feet digging\" method for sampling the sandy beach bivalve Donax deltoides was evaluated by comparison to quadrat-based results from eleven beaches in subtropical eastern Australia. The method was developed from a recreational fishing technique that involves twisting ones feet into the thixotropic sand to dislodge buried clams which are then recovered by hand. Several plots are sampled across the swash zone in one five-minute sampling unit and the process is replicated at several locations along the beach. Mean feet digging clam counts were proportional to mean transect linear clam densities (r = 0.98). Clam length-frequency distributions from feet digging were similar to those from quadrat sampling except that feet digging was not effective for clams < 16 mm. Feet digging counts are sensitive to both across shore (tidal) and alongshore variation in clam abundance and were less precise than those from quadrat-based methods (CV 1.2x larger). However, feet digging is fast and the method should be useful for low cost surveys of Donax deltoides and similar \"surf clams\".

ecology↗

bioRxiv2019

Seasonal zonation patterns of the sandy beach bivalve Donax deltoides (Bivalvia: Donacidae) in subtropical eastern Australia

Seasonal low tide zonation patterns of the sandy beach bivalve Donax deltoides are described from eleven beaches in subtropical eastern Australia. Ten low tide transects were sampled at equal along shore intervals along the length of each beach. Three quadrats were sampled at each of seven across shore levels on each transect, from the high tide drift line, across the intertidal zone and to the bottom of the low tide swash zone. Zone counts showed that D. deltoides shifted towards the low tide swash zone in summer and buried in the intertidal zone in winter. It is proposed that D. deltoides moves down shore in summer to avoid thermal stress in the intertidal zone. This seasonal pattern is important when planning surveys for this species.

ecology↗

bioRxiv2019

Estimating the abundance of benthic macrofauna from across shore transects

Benthic macrofauna of the intertidal zone are commonly sampled at low tide by excavating and sieving quadrats or cores on across shore transects. This paper examines different equations for estimating transect scale abundance, introduces the sampling theorem for calculating the maximum sampling interval and uses simulations to investigate sampling issues. Adaptive transect designs are recommended, where the sampling interval and replication of quadrats are carefully selected according to the width and density of macrofauna bands.

ecology↗