## 4 Discussion
### Management Perspectives  
The assessment of the sustainability of beam trawling's impact on benthic species is a crucial part of an ecosystem-based approach to fisheries management (EAFM), as bottom-dwelling species contribute to the benthic-pelagic coupling (i.e., the flow of organic matter from the water column to the seabed), are habitat engineers, and are a significant source of food for demersal fish [58]. Fishery management strategies that incorporate limitations on fishing effort and gears over time and space are essential tools for addressing this issue [59]. Temporal and/or spatial closures have been indicated as approaches to mitigate overfishing-related disturbances and to promote biodiversity recovery and ecosystem restoration [66].  
The EAFM calls for managers to take the environmental effects of fishing into account in management plans [67]. However, the associated management measures may displace fishing activity. The consequences of this could be evaluated using information on the distribution of recovery rates of various benthic habitats. As a result, MPA management plans that limit beam trawling to more resilient areas and maintain permanently unfished patches within these areas should minimize the effects of MBCG fishing efforts on seabed habitats. The speed of habitat recovery can be increased by keeping patches of nearby habitats unfished [68].  
Other significant biological benefits, such as the prevention of habitat degradation that invariably follows the use of MBCG such as beam trawls, can result from fishery management systems that regulate the use of certain types of fishing gears, in addition to the obvious benefits for targeted species (deep sea mussel beds, in the case of ROSCI0066).  
It is crucial to bear in mind that trawling has a greater negative impact on benthic species in areas that have not yet experienced it than it does in areas that have. The severity of the impact will also depend on how frequently and intensely natural disturbances occur [58]. Consequently, management measures that displace trawling effort from existing fishing grounds can have significant effects on benthic communities [69], the magnitude of these effects being determined by trawling frequency, and the frequency and intensity of natural disturbance. The preservation of sensitive benthic habitats is one of many management objectives for which area closures have been proposed [69]. It is known that rotational management and area closures enable benthic fauna to recover from the effects of fishing [70].  
Even though the deep-sea mussel beds are included in an MPA under national and European legislation (Danube Delta--Marine Zone ROSCI0066), they are not currently protected from beam trawling, as this type of fishing is banned only at depths below 20 m (near the coast), while most of the beam trawling activity overlaps with deep-sea mussel beds in the 25-30 m bathymmetric zone. The revised Management Plan of the Danube Delta Biosphere Reserve (currently under appropriate assessment by the Romanian Environmental Agency) advocates for establishing certain Fisheries Restricted Areas (FRAs) beyond the 20 m isobath. The restrictions consider both temporal and spatial bans within the Danube Delta--Marine Zone, by alternating defined areas undergoing fishing with biological recovery polygons. The selection of these areas should be completed only after performing dedicated studies to assess the impact of beam trawling on the seabed in ROSCI0066, with a particular focus on circalittoral muds with _M. galloprovincialis_.