Have you ever travelled to a coastal destination and found cute little seahorses used as jewellery or decorations? What about seeing live seahorses in tanks for sale? While the sale of seahorses is a legal and common practice, the way seahorses are captured and the status of their population need to be monitored in order for this practice to be sustainable. As a popular specimen for aquariums, souvenirs, and Traditional Chinese Medicine (TCM), overharvesting these creatures threatens their populations. At least 35% of all seahorse species are endangered, vulnerable, or near threatened, according to the IUCN Red List of Threatened Species. Two of the major causes threatening seahorse populations are overharvesting of seahorse populations due to increased demand in the international aquarium trade industry and habitat degradation from coral bleaching as a result of climate change. You can help conserve these animals by knowing the dos and don’ts of purchasing live seahorses or seahorse products and changing a few behaviours in your own life.
Targeted Fishing
Historically, seahorses have typically been captured as fishery by-catch, especially from shrimp trawling; however, economic motivation for seahorses has increased fishing methods that specifically target seahorses. China is one of the main consumers of seahorses as they are used in TCM. With increasing demands for TCM, seahorses are being taken from their populations faster than they can reproduce. While the capture of seahorses for use in TCM, souvenirs, and aquariums is legal, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) implemented trade regulations on seahorses in 2004, meaning that while trade continues, it has to be managed and wild populations need to be monitored. So how do you know if you’re buying seahorses that have been legally traded? Seahorses for sale as souvenirs should not be smaller than 10 centimeters long, according to CITES. This is to ensure that the breeding generations and juveniles are left in the wild to repopulate. Unfortunately, this regulation is, and continues to be broken, as juvenile seahorses were found throughout the international aquarium trade market after CITES implemented this regulation. This is most likely because of illegal harvesting and smuggling, which goes to show why it is even more important to be knowledgeable about what you are buying. The CITES regulations are working top-down to protect seahorse species from illegal trade, so it is up to the consumers to control the bottom-up demand for legal seahorses. The international aquarium trade industry has also caused extreme ecological impacts, such as destruction of habitat, the introduction of non-native species, and plastic pollution from fishing equipment. Therefore, encouraging the responsible and safe acquisition of seahorses can have a more positive effect on the environment as a whole.
Habitat Loss and Coral Bleaching
Naturally, seahorses are found in seagrasses, mangroves, estuaries, lagoons, macroalgae, and coral reef habitats. As water systems become more and more polluted and harmful algal blooms threaten the success of these habitats, an increased number of seahorse species will face extinction due to habitat loss. Coral reefs are an important habitat for seahorses because they use branches of the coral and other coral structures to grab onto with their tails, keeping them from floating into open waters. Coral shares a beneficial relationship with certain bacteria and algal symbionts, but biotic and abiotic stressors can cause this healthy relationship to break down, leaving the coral to suffer. Such stressors include the increase in water temperature due to climate change, changes in pH, and increases in pollution. One of the leading stressors causing habitat loss is increased water temperatures. Furthermore, hurricanes and increased sedimentation and nutrient pollution due to poor land-use practices are also responsible for the loss of coral.
Many actions by humans can increase the amount or pressure of these stressors. Think about what climate change means: a changing climate. You may have experienced the results of this with warmer summers, earlier springs, less rain, etc., but have you thought about what it means worldwide? Not only are your actions impacting your immediate environment, but the ecosystems of the world are connected in one way or another. Just like if the coral reefs could no longer support a diverse habitat for fish, humans would feel the effects in the fishing industry, putting more pressure on other food industries and so on.
Coral loss not only affects seahorses, but the entire reef community. If coral is experiencing stress from outside factors, those same stressors could also be impacting seahorses. Just like the coral, when seahorses are exposed to stress they become more susceptible to disease. While seahorses can be found in other types of habitat, they may or may not be facing the same threats as coral reefs. The removal of reef ecosystems from seahorse’s available habitats would be like removing a continent available for humans to live on. With fewer options, seahorses will face declining populations.
A Positive Outlook on the International Aquarium Trade
With seahorses being the first fully marine fish species implemented in CITES regulation of trade, it acts as a flagship species for other near-threatened, or endangered marine species that may, too, become regulated by CITES. The international aquarium trade has begun to relieve the pressure of overharvesting and targeted fishing of seahorses through the use of captive-bred seahorses over wild-caught methods. This shift from wild-caught to captive-bred seahorses shows that the international aquarium trade industry is moving in a more sustainable direction. Until captive-bred seahorses can support the demand for seahorses in the aquarium trade industry, wild seahorses need to be monitored and protected from overharvesting. Although it is impossible to patrol every mile of the ocean to make sure this requirement is met, consumers can lessen the demand for seahorses of smaller size, hopefully influencing which seahorses are targeted.
Reducing Environmental Stress
When faced with environmental stress, corals are showing resilience and adaptability by altering their interactions with the microbial community, allowing themselves to withstand changes in temperature. Without environmental stress, coral may be able to maintain a truly symbiotic relationship with the microbial community. A healthy reef ecosystem would provide the necessary habitat for zooplankton and other food sources for seahorses. To help seahorses counteract the loss of habitat, artificial habitats are also being used to support seahorse populations. Although artificial habitats in the wild are not regularly successful in increasing biomass, it is suggested that these may be used to recover endangered species in areas where natural habitats have declined. While the coral reefs are trying to adapt to our rapidly changing environment, we as humans need to do our part to reduce the stress and impacts we have on climate change.
What Can You Do?
Not everyone will be put in the position to responsibly purchase seahorses for aquariums, souvenirs, or TCM. Whether you are an avid traveler, first-time tourist, or prefer the comforts of home, there is something we all can do in our daily lives to help protect seahorses from extinction. Climate change is happening all around us, so we need to work together to slow its damaging effects. Reducing the rate of increasing water temperatures is an important step in protecting seahorses. Preventing pollution from entering our water system can be done by disposing of waste properly and keeping chemicals, oils, and fertilizers, from washing directly into storm drains. Efforts to reduce greenhouse gas emissions by using renewable energy and energy-efficient light bulbs, washing clothes in cold water and line drying, and planting native plants also work to hinder the increase in water temperatures.
As a traveler, make sure to only use reef-safe sunscreen, even if you’re not directly swimming in reefs. Look into ways you can offset the carbon emissions of traveling either in the country you’re traveling to, or at home. Some examples might be planting trees, eliminating single-use plastics from your daily life, and reducing emissions by using public transit, carpooling, biking, or walking. We want this ecosystem to be healthy not only for the seahorses and other species that live here but so we can enjoy its beauty for many generations to come.
About Rebecca Scherr
Rebecca Scherr is in the Environmental Professionals Advanced Training Program at The Dawes Arboretum in Newark, Ohio. She is also a graduate student studying conservation biology with Project Dragonfly at Miami University in Oxford, Ohio.
References
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Convention of the International Trade in Endangered Species of WIld Fauna and Flora (CITES). (2019). Seahorses (Hippocampus spp.) on CITES- A Roadmap to Success. https://www.iucn-seahorse.org/cites-toolkit
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Vincent, A. C. J., Foster, S. J., & Koldewey, H. J. (2011). Conservation and management of seahorses and other Syngnathidae. Journal of Fish Biology, 78(6), 1681–1724. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1095-8649.2011.03003.x
This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media