Macroalgal mats in a eutrophic estuarine marine protected area

Authors: Thornton, A., Herbert, R.J.H., Stillman, R.A. and Franklin, D.J.

Pages: 703-727

ISBN: 9780081026991

DOI: 10.1016/B978-0-08-102698-4.00036-8


Green macroalgal mats are a consequence of increased nutrient input into estuarine ecosystems and can cover extensive areas of intertidal habitats. The extent and biomass of mats is a key metric for estuarine ecological condition assessment. We measured macroalgal mats in Poole Harbour Marine Protected Area (MPA) from 2013 to 2015. Peak biomass reached gt;2 kg m-2 and persisted at gt;1 kg m-2 with gt;50% coverage throughout both seasons. Intertidal mudflats in Poole Harbour MPA contain an abundance and diversity of benthic macrofauna providing a vital prey resource for 20,000 overwintering wading birds. Overall invertebrate abundance declined when macroalgal mat biomass gt;800 g m-2. Dense macroalgal mats persisted into autumn thereby coinciding with the arrival of the overwintering wading birds. This level of coverage, combined with reduced prey energy, could lead to a decline in the designated feature with implications for the UK’s binding agreements, and lead to sanctions under current legislation.

Source: Scopus