New opportunities for conservation of a threatened biogenic habitat: a worldwide assessment of knowledge on bivalve-reef representation in marine and coastal Ramsar Sites

Abstract

The present study draws attention to the current state of knowledge of bivalve reef, an important but historically overlooked habitat type. Recent interest has led to the explicit recognition of this habitat type under the Convention on Wetlands of International Importance (the Ramsar Convention), an international treaty that has widespread governmental and scientific involvement. To assess the state of knowledge, the Information Sheet on Ramsar Wetlands (RIS) for marine and coastal Sites was searched for evidence that bivalve-reef habitat is present in the site. We then examined the quality of this information using alternative data sources. These were public databases of geolocated species records at three spatial scales, local and regional experts, and a general web search. It was found that of the 893 marine and coastal Ramsar Sites considered, the RIS for 16 Sites provided strong evidence of bivalve-reef habitat and 99 had confirmed presence of reef-forming bivalves, a strikingly high number, given that it is not yet compulsory to include bivalve reef in RISs. However, the alternative information sources identified bivalve reefs or reef-forming bivalves in 142 further Sites. No one information source provided comprehensive information, highlighting the overall poor state of knowledge of this habitat type.