A model approach to estimate the potential for mussel beds in a Wadden Sea area of the German North Sea coast

Malte Rubel,Julian Sievers,Peter Milbradt,Klaus Ricklefs

doi:10.5194/egusphere-egu2020-3574

Abstract

&lt;p&gt;In the awareness of the increasing conciousness regarding the sensitivity, vulnerability, and&lt;br&gt;complexity of near coastal marine ecosystems, including tidal flats, it is imperative to improve the&lt;br&gt;understanding of its individual elements. One of these elements are organisms habitating the&lt;br&gt;seabed, such as mussels.&lt;br&gt;Bivalves - specifically blue mussels (Mytilus edulis) and pacific oysters (Magallana gigas) - besides&lt;br&gt;other smaller organisms are an integral part of the seabed fauna. On the one hand they serve as a&lt;br&gt;basic food resource for a large number of higher trophic level predator. On the other hand they&lt;br&gt;affect the surface structure, stability and composition of the seabed.&lt;br&gt;To better understand the large fluctuations the mussel stocks underwent during the last decades, it is&lt;br&gt;of great benefit to know the environmental conditions of their habitats. Based on the analysis of&lt;br&gt;different physical parameters at known mussel beds, prototypical automated algorithms were&lt;br&gt;developed and used to identify other tidal flat regions with favorable conditions for epibenthic&lt;br&gt;mussels. The input parameters originate from different morphological, hydrodynamical,&lt;br&gt;sedimentological and hydrochemical numerical models. Morphological factors include&lt;br&gt;morphological activity and gradient conditions of the ground surface, hydrodynamical factors&lt;br&gt;include stream velocities, bottom shear stress, wave orbital velocities, energy of wave breaking and&lt;br&gt;duration of tidal flats falling dry during low tide, sedimentological factors include sediment&lt;br&gt;composition and hydrochemical factors include salinity. These parameters were available as&lt;br&gt;products of the mFUND project EasyGSH-DB and were supplemented with additional evaluations.&lt;br&gt;It is expected that the approach of habitat modeling will allow to determine the possibility of initial&lt;br&gt;and long-term settlements of epibenthic mussels by ruling out intertidal or subtidal seabed areas&lt;br&gt;where environmental parameter combinations do not fulfill the necessary requirements.&lt;/p&gt;

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