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Recovery of macrobenthic communities after maintenance dredging in the Blyth Estuary, north-east England

✍ Scribed by M.P. Quigley; J.A. Hall

No coin nor oath required. For personal study only.

✦ Synopsis

This paper examines the impact of a dredging event on the benthic community of a polluted estuary in north-eastern England and follows recovery of the community from January until June, 1997.
Adopting a BACI (Before, After, Control, Impacted) approach, the benthos were sampled at two sites using a Haps corer (0.0143 m 2 ). Five cores were taken at each site, and the sites were each visited once in January 1997, prior to the 33 day dredging period, and a further five times during the 100 day post-dredging monitoring period ending in June 1997.
Fifteen taxa were recorded, of which five contributed 95% of all of the individuals present; Capitella capitata (Fabricius), Tubificoides spp., nematodes, Eteone longa (Fabricius), and the mollusc Angulus tenuis (da Costa).
Univariate and multivariate analyses of benthic macrofaunal data showed that dredging had not only impacted the dredged site, but had also affected the control area located 500 m away on the opposite side of the estuary. At the end of the study period the macrobenthic community at the impacted site showed no significant signs of recovery to pre-dredging community parameters.