Gone and Back—The Anthropogenic History of Coccotylus brodiei (Turner) Kützing and Furcellaria lumbricalis (Hudson) J.V. Lamouroux in the Gulf of Gdańsk (Southern Baltic Sea)

Abstract

The Gulf of Gdańsk environment has supported the development and growth of the local community for centuries but has been significantly degraded as a result of the progressive eutrophication process that started in 1960, the extensive exploitation of marketable species (plants and fish) and pollution limiting the growth of marine organisms. Multistressors of the Anthropocene era have left their mark on all aspects of the ecosystem, but despite this, the gulf region has been considered to have exceptional environmental value and high biodiversity in comparison with adjacent regions. In 2004, a Natura 2000 site was created in the eastern part known as Puck Bay, and actions were taken to protect endangered habitats and species. Between 2019 and 2020, intensive field studies were conducted in Puck Bay on flora to assess biodiversity and habitat resources. The material was collected for qualitative and quantitative analysis. This allowed observation of species that have not been reported since the 1970s, i.e., Coccotylus brodiei (Turner) Kützing and Furcellaria lumbricalis (Hudson) J.V. Lamouroux. Both species co-occurred as in the period before the 1960s in the form of free-floating thalli. The rediscovery of these taxa suggests that despite very unfavourable conditions for their development due to anthropogenic pressures, they were able to survive, and their occurrence throughout Puck Bay indicates improvement in environmental quality due to declining human impact. Our results indicate that benthic algal communities have high regeneration potential, but in the case of severe environmental degradation caused by synergistic pressures of high intensity, plant recovery without measures to support remediation takes at least 30 years.