Shipwrecks are now protecting sea turtles, dolphins and other crucial marine creatures from bottom-towed fishing

Beneath the tranquil waves of the UK coastline lies a hidden sanctuary for marine life: a network of approximately 50,000 shipwrecks, silent sentinels of a bygone era, now playing a crucial role in safeguarding marine biodiversity.

In areas where bottom-towed trawling — a destructive fishing practice that rakes the seabed — remains prevalent, shipwrecks have emerged as havens for a diverse array of marine creatures, including fish, corals and other invertebrates.

Bottom trawling is a method of industrialised fishing that remains steeped in environmental controversy. Since it involves indiscriminately dragging heavy fishing gear across the seabed, experts are concerned that they can severely destroy large expanses of habitats that sprawl the sea bottom. Further, the method also hauls tons of “undesirable" by-catch, which get killed accidentally in the process. Often, the by-catch includes protected species such as sea turtles, sharks and dolphins.

But in a unique twist of fate, the very ships that might've contributed to ecological degradation in the past have become the newest havens protecting the region's biodiversity. Due to the inability and reluctance of fishers to bottom-trawl in the region, the study found that within shipwrecks and the surrounding 50-metre radius, the abundance of marine life soared by a staggering 240% compared to actively trawled sites.

This protective effect was even more pronounced within a 50-metre radius of shipwrecks in areas with some fishing restrictions, with marine life densities surging by an impressive 340%. These shipwrecks, all dating back to the late 19th and early 20th centuries, are constructed from a variety of materials and rest between 17 and 47 metres beneath the ocean surface, providing unique habitats for a multitude of species.

Whether human-made or not, we need to start looking at shipwrecks as vital refuges for marine species. As the UK strives to achieve its goal of protecting 30% of its oceans by 2030, understanding the ecological significance of shipwrecks and the effectiveness of marine protected areas becomes increasingly crucial.

The findings of this research have been published in Marine Ecology and can be accessed here.