Abstract

Until the late 19th century, extensive beds of flat oyster Ostrea edulis populated the Central North Sea, which have vanished after intensive fisheries. At present, various initiatives are being carried out to investigate the potential to restore this former key species in the area. This historical ecological study contributes by delineating the former oyster bed area and through an assessment of its limits against known gradients in the North Sea. Extensive data from historical maps, texts, and ship-based surveys were used to synthesize our knowledge on the former beds. It was revealed that the area with oyster beds covered ∼6.2% of the total North Sea bottom, with a delineation that could partly be explained by hydrodynamic and temperature gradients. The position and extent of the area are notably different from the area that is used in recent feasibility studies on the restoration of North Sea oyster beds. The offshore oysters lived on muddy sand in relatively cold conditions, and there are several indications that their reproductive rate was low. The apparent disappearance of cold water adapted flat oysters will challenge restoration projects. This study provides indispensable information for the future restoration of flat oyster beds in the North Sea.

中文翻译：

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北海中部的可食用的Ostrea edulis床：划定，生态和修复

摘要

直到19世纪后期，大量的扁平牡蛎可食用牡蛎在密集的渔业之后消失的中北海。目前，正在采取各种举措来调查恢复该地区以前的主要物种的潜力。这项历史性生态研究通过描绘出先前的牡蛎床区域并针对北海已知坡度评估了其极限而做出了贡献。来自历史地图，文本和基于船的调查的大量数据被用来综合我们在前几张床上的知识。结果表明，牡蛎床面积约占北海总面积的6.2％，其轮廓可以部分用流体动力学和温度梯度来解释。该区域的位置和范围与最近在恢复北海牡蛎床的可行性研究中使用的区域明显不同。近海牡蛎在相对寒冷的条件下生活在泥沙中，有许多迹象表明它们的繁殖率很低。适应冷水的扁平牡蛎的明显消失将对恢复项目构成挑战。这项研究为将来在北海恢复牡蛎平床提供了必不可少的信息。