The Impacts Of Using Aquatic Mammals As Fishery Bait

In the West, marine mammals like whales, dolphins, otters, and seals are usually shown as highly intelligent and sociable animals that should be protected. Images of oil-covered otters or plastic-choked whales are common in environmentalist campaigns, which highlight the dangers posed by pollution and climate change. However, those are not their only threats: a new study has revealed that the killing of marine mammals for use as bait is a relatively common practice in much of the world.

In this study, researchers examined 145 reports, academic studies, and newsletters dated from 1970 to 2017, to ascertain where and when this practice took place, as well as what species were affected. They found that in this time period, the practice has been recorded in 33 countries, targeting 42 different species of marine mammal. 39% of these countries are in Latin America, and 27% are in Asia. 66% of species listed as used for bait were used in fisheries targeting sharks. 83% of species were targeted deliberately in at least one country, and 70% of listed nations had at least one fishery that intentionally targeted cetaceans (whales, dolphins, and porpoises).

In Argentina and Chile, cetaceans were used as bait in crab traps through the 1980s, but this practice has waned. Brazilian fisheries, however, continue to use dolphins and whales as shark bait, especially along the Bahia coast. In Peru, intentionally catching cetaceans has been forbidden by law since 1996. However, this law has done little to reduce by-catch, which is frequently used as shark bait; there is also little incentive to avoid by-catch. In the Indo-Pacific, the practice is widespread, especially in Indonesia, the Philippines, Taiwan, and Tanzania. In large river systems like the Amazon and Orinoco, river dolphins are hunted and used as bait for catfish.

While intentionally killing whales and dolphins is illegal in most countries where this practice is recorded, it generally continues in areas with limited law enforcement and low economic development.

Of course, the practice can have serious consequences for the species affected: around 27% of marine mammal species used as bait are listed as vulnerable or endangered, including the vaquita porpoise, sperm whale, Ganges river dolphin, and marine otter. In addition, 30% of the species that bait mammals are used to lure, are themselves threatened. Shark, catfish, and crab fisheries are the lead consumers of marine mammal bait.

Most of the fisheries in Latin America and Asia that use cetaceans for bait are located in countries with a medium or high human development index (HDI) by the UN. In lower-HDI countries, particularly those in West Africa, marine mammals are more likely to be consumed directly by humans than used as bait for other animals.

Again, many of the countries in which cetacean meat is harvested for bait outlaw the intentional killing of whales or dolphins. However, much of the actual killing takes place far from the reach of the government or occurs as by-catch of legal fishing. Without proper enforcement and oversight mechanisms, laws are ineffective.

The researchers note that improved infrastructure and competent law enforcement could help deter many from killing marine mammals. This can be shown by the decline of whaling in New Zealand and the Mediterranean: strong laws, combined with changing public attitudes, effectively ended the practice. Enforcement is not enough, however; economic demands have to change. If marine mammals are worth more to the community alive than dead, there is no longer an incentive to use them as bait. This is the path taken by the Maldives and Zanzibar, where shark fisheries were largely replaced by eco-tourism.

The researchers note that while the eco-tourism industry has its own environmental problems, they are less serious than those of overfishing. Proper regulation of the eco-tourism industry results in minimal ecological damage and can improve the health of a damaged ecosystem.

The researchers note – and this will especially interest conservation advocates – that environmental education is vital. Many of these fisheries are unknowingly driving themselves out of business through overfishing, and if fishing communities are taught the important role that sharks and cetaceans play in the health of their ecosystems, they would be less likely to overfish or use endangered species as bait. However, like other solutions, this is likely not enough on its own.

When forced to choose between the health of the environment and their livelihood, most will choose their livelihood. For this reason, there needs to be a replacement livelihood created for those communities which rely on cetacean bait, and the aquatic species they try to catch with it. An economic climate must be created such that people will be able to preserve the survival of marine mammals without endangering their own.