Decades of protection measures show results: Increasingly, sand tiger sharks are being sighted in Boston Harbor. Scientists report that the waters are significantly cleaner today than before, and more prey fish are settling, creating ideal conditions for the sharks to use the area as a nursery.
Young sharks in focus of research
Researchers from the New England Aquarium catch juvenile sand tiger sharks to fit them with small transmitters. These send signals to buoys along the US East Coast, allowing the movements of the animals to be tracked. During the procedure, the sharks enter a state of tonic immobility, which makes the process easier. After the transmitters are fitted, the sharks are immediately released.
Sand tiger sharks can grow over three metres long but in Massachusetts only appear in the summer as juveniles. They feed exclusively on fish and pose no danger to humans. Many visitors are not even aware that these animals are present in the harbour.
From decline to slow recovery
In the 1970s to 1990s, populations declined by up to 90 percent due to fishing. Only with a ban on fishing in the 1990s did a slow protection process begin. Today, the population is recovering by one to two percent per year, a small but significant progress.
The return of the sharks is also linked to the improvement in water quality in Boston Harbor. Decades of environmental measures have made the habitat more attractive again, so that the sharks now regularly return. Some of the tagged animals migrated hundreds of miles to Florida and later returned to exactly the same stretch of coastline – an impressive demonstration of this species’ attachment to specific habitats.
Sand tiger sharks deserve more attention
While great white sharks in New England often take centre stage in public attention, experts point out that other species, such as the sand tiger, urgently need more research and protection. Their role in the ecosystem is crucial, yet much remains unknown about their behaviour and population trends. The new transmitters, which can provide data for up to ten years, should help close these knowledge gaps and develop better long-term protection measures.
