Introduced fish species have been dominating the Philippine inland freshwater for over three decades now and no formal risk assessment efforts have been put up so far to assess the potential adverse effects of this invasion process could have on human and our environment.

This strongly sounds as an alert after NRCP researcher and fishery expert Dr. Maria Lourdes C. Aralar pointed to the non-inclusion of risk assessment and management component in the government’s efforts to tackle the issues associated with introduction of species, with emphasis on species which have the potential to become invasive alien species (IAS) particularly in the fishery sector. Dr. Aralar is a scientist at the Southeast Asian Fisheries Development Center (SEAFDEC) and specializes in aquatic ecology and toxicology.

In her presentation during the recent scientific session of the NRCP Biological Sciences Division, Dr. Aralar reported that local fish farmers have shifted to growing introduced fish species, which now makes up about 98% of our total freshwater fish production.

Invasive alien species (IAS) are plants, animals and other organisms that are non-native to an ecosystem, which may cause economic and environmental harm and adversely affect human health. Biodiversity scholars and advocates consider IAS to be the main direct drivers of biodiversity loss across the globe.

The introduction of alien species in our aquaculture has brought considerable enhancement to our fishery industry in terms of livelihood and economy. Among the most important introduced freshwater aquaculture species in the Philippines are tilapia and carps. Milkfish, whose natural habitat is the marine environment, is also considered an introduced species in Laguna de Bay, the largest inland water body in the country. The Food and Agriculture Organization Database on Introductions of Aquatic Species (FAO DIAS) ranked Philippines in SE Asia as the number one recipient of aquatic species introductions, with 76 fish species, 20 mollusc, 10 crustacean and 5 seaweed species.

While the introduction of alien species significantly contributed to our country’s efforts to attain and sustain food security, many of these introduced fishes have become invasive and caused ecological damage and “extirpation” of native species.

Extirpation or removal (destruction) of native species from and in its natural habitat is the result of competition and predation by invasive species. IAS could also carry with them pathogens and parasites that can cause diseases and infections in the native wildlife and humans.  Studies indicate that invasive species became successful invaders and colonizers because they serve as vector for parasites that could kill the native species.

There is broad agreement among many scientific literatures that invasive species have adverse impacts on biodiversity and cause billions of dollars worth of economic loss on a global scale.

Risk assessment and management could serve as first line of defence against unwarranted effects of introduced species according to Dr. Aralar. She added that risk assessment should be carried out in a scientifically sound manner with the use of recognized risk assessment tool.

In the US, the National Invasive Species Council manages and coordinates all domestic efforts and risks associated with invasive species.

In the Philippines, the Department of Environment and Natural Resources initiated in 2015 the National Invasive Species Strategic Action Plan (NISSAP) as part of its campaign against illegal wildlife trade and prevention of the entry of exotic wildlife that can potentially become invasive species. However, the scope of the Plan is limited to preventing the introduction and spread of IAS in natural habitat and government protected sites.

But how do we start developing our own risk assessment measures?

“Somebody has to start doing it and research about it,” Dr. Aralar said.

“We also need to reduce our dependence on alien species for aquaculture. One way is to enhance efforts on the domestication of commercially important local species. Clearly, sound policies and improved legislation on these efforts are urgently needed, she added.

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