**1. Introduction**

An exotic organism or a non-native organism is a plant or animal that has been transplanted by humans; they are usually perceived from a negative point of view [1]. The International Union for Conservation of Nature [2] describes Alien species (non-native, non-indigenous, foreign, exotic) a species, subspecies, or lower taxon occurring outside of its natural range (past or present) and dispersal potential

(i.e., outside the range it occupies naturally or could not occupy without direct or indirect introduction or care by humans), which includes any part, gametes, or propagule of such species that might survive and subsequently reproduce. On the other hand, Invasive alien species (IAS) are species whose introduction and/ or spread outside their natural past or present distribution threatens biological diversity which occurs in all taxonomic groups, including animals, plants, fungi, and microorganisms, and can affect all types of ecosystems [3]. Generally, exotic species are regarded as IAS.

IAS is one of the five most important direct drivers of biodiversity loss and change in ecosystem services [4]. According to the Invasive Special Specialist Group, [5], IAS can interact with migratory species in several ways resulting in cumulative negative impacts, for example, as a threat on their breeding sites, on their stopover and wintering grounds, and during migrations. These impacts may result in local extinction or decline in population numbers as well as changes to migration patterns. IAS impacts native species (including migratory species) and their habitats through several mechanisms, including predation, habitat degradation (grazing, herbivory, browsing, rooting/digging and trampling), competition, hybridization, disease transmission, parasitism, poisoning/toxicity, biofouling, etc. IAS has resulted in major impacts on biodiversity at a global scale, where at least 39% of the species extinctions during the past 400 years are due to IAS [6].

The importation of alien or exotic aquatic species from other countries is continuing in the Philippines. Most of the importation is for aquaculture and the aquarium trade. Exotic species are either purposely or accidentally introduced in rivers and lakes which are inhabited by endemic and indigenous fish species. Most of these introductions have contributed negative impacts on freshwater/wetland ecosystems and have caused biodiversity loss [7, 8], while some introduced species have contributed a significant proportion to aquaculture in the Philippines [9]. In terms of such contributions, the Nile tilapia *Oreochromis niloticus* is next to milkfish *Chanos chanos* among the aquaculture species, followed by the big head carp *Aristichthys nobilis* [10].

There are 181 organisms (28 families) introduced of exotic aquatic species since the 1900s; however, 40 organisms have unknown records of introductions in the Philippines [11]. In 2018, the IUCN Invasive Species Specialist Group [12]'s Global Invasive Species Database (GISD) lists 84 alien species, 12 with bio status unspecified and 54 that are native to the Philippines. The Pacific whiteleg shrimp *P. vannamei* is not included in the list; however, published studies reported the risk of culturing the shrimp outside its natural geographic range. For intensively farmed *P. vannamei* in Indonesia, the final numerical score is 3.39 out of 10, where the presence of three red criteria (Habitat, Chemicals, Disease) results in an overall red "Avoid" recommendation. Red mark means that these items are overfished or caught or farmed in ways that harm other marine life or the environment [13].

*P. vannamei* [14] is native to the Eastern Pacific coast from the Gulf of California, Mexico to Tumbes, North of Peru [15]. In the Philippines, *P. vannamei* was imported from Panama in the 1970s and from Hawaii in 1990 [16, 17]. However, there was no documentation of these introductions because government regulations were not followed in most cases, and it was not known whether the exotic species introduced any new pathogens [18].

Risk can be defined as the likelihood of harm occurring as a result of an action or inaction [19]. Harm refers to the undesirable consequences to humans or components of a valued ecosystem [20]. However, Senanan et al. [21] argued that there is a challenge in analyzing the ecological risk of alien species because of difficulty in predicting the harm, estimating the likelihood of harm occurring and the severity of the harm. These parameters are species and ecosystem specific and are

**145**

*Ecological and Social Impacts of Aquacultural Introduction to Philippines Waters of Pacific…*

often difficult to measure. The analysis would describe the ecosystem components (abiotic and biotic) and relevant processes, life history characteristics of the alien species and the relevant interaction between the two, drawing on existing data and

The presence of Pacific whiteleg shrimp *P. vannamei* in the Philippines has already reached more than five decades, and this raises risk and environmental concern. This is timely relevant to the theme of the book *Spatial Variability in the Environmental Sciences - Patterns, Processes, and Analyses* which covers the topics on migration, extinction, disturbance, restoration, contamination, conservation, pollution, revitalization, growth, and decline. Thus, this review paper aimed to determine the ecological and social impacts of aquacultural introduction to the Philippines waters of Pacific whiteleg shrimp *P. vannamei*. The preliminary risk analysis of the releases of *P. vannamei* guided with several questions reported by Senanan et al. [22] was adopted to evaluate the ecological impacts, while social impacts were evaluated based on literature. Guide questions include (1) "How many *P. vannamei* have escaped?", (2) "Can escapees survive in the natural environment?", (3) "Can escapees establish a natural population?", (4) "What is the extent of the geographic spread of the alien pathogen, Taura syndrome virus (TSV)?", and (5) "Can *P. vannamei* potentially compete with native shrimp species?". The questions were answered and discussed based on literature, scientific details, reflections on personal experience, and their relevance to aquaculture of the *P. vannamei* in the Philippines. Conclusions were formulated based on the interpreted findings of this review, and recommendations were made for sustainable aquaculture of *P. vannamei* in the Philippines.

There have been numerous reports of escapes from aquaculture production facilities into non-native waters. The presence of *P. vannamei* has been reported in Texas, South Carolina, and Hawaii, USA [23–28]; Thailand [29, 30]; Venezuela [31]; Brazil [32]; Puerto Rico [33]; Vietnam [34]; and Southern Gulf of Mexico coast [35]. In the Philippines, Briggs et al. [29] reported that a population of *P. vannamei* already exists in the wild through intentional release and escapes. The implementation to ban the importation of all live shrimp and prawn species of all stages except for scientific or educational purposes by the Bureau of Fisheries and Aquatic Resources (BFAR) in 1993 led to illegal importation in 1997 by private sector due to disease problems with the culture of *P. monodon*, and the regulations are known to have resulted in the dumping of PL *P. vannamei* into the wild in attempts to escape detection. Also, typhoons have also resulted in the liberation of *P. vannamei* from culture ponds into the surrounding sea. On average, 20 typhoons hit the Philippines

every year, and some of the most destructive and deadliest typhoons include Yolanda (2013), Pablo (2012), Sendong (2011), Ondoy (2009), Frank (2008), Milenyo (2006), and Reming (2006) (http://bagong.pagasa.dost.gov.ph/). Based on the main author personal experience, *P. vannamei* has been sometimes a part of catch by local fisherman in Buguey Lagoon, Cagayan. Its presence in the lagoon is possibly due to the escape from the Dataj Aquafarm which is actively engaging in the grow-out of *P. vannamei* in four different locations in the municipality of Buguey and Camalaniugan with a total area 77.91 hectares. The lagoon serves as the main water source of the farms. More frequent flood incidence in the area is taking place especially during typhoons or heavy rains due to black sand mining that

Through the years, the culture of *P. vannamei* in the Philippines is continuously growing even during the implementation of the shrimp importation ban from 1993

started in 2009 until 2013 that widens the mouth of the lagoon.

*DOI: http://dx.doi.org/10.5772/intechopen.91775*

**2. How many** *P. vannamei* **have escaped?**

literature, as well as specific experiments and field surveys.

*Ecological and Social Impacts of Aquacultural Introduction to Philippines Waters of Pacific… DOI: http://dx.doi.org/10.5772/intechopen.91775*

often difficult to measure. The analysis would describe the ecosystem components (abiotic and biotic) and relevant processes, life history characteristics of the alien species and the relevant interaction between the two, drawing on existing data and literature, as well as specific experiments and field surveys.

The presence of Pacific whiteleg shrimp *P. vannamei* in the Philippines has already reached more than five decades, and this raises risk and environmental concern. This is timely relevant to the theme of the book *Spatial Variability in the Environmental Sciences - Patterns, Processes, and Analyses* which covers the topics on migration, extinction, disturbance, restoration, contamination, conservation, pollution, revitalization, growth, and decline. Thus, this review paper aimed to determine the ecological and social impacts of aquacultural introduction to the Philippines waters of Pacific whiteleg shrimp *P. vannamei*. The preliminary risk analysis of the releases of *P. vannamei* guided with several questions reported by Senanan et al. [22] was adopted to evaluate the ecological impacts, while social impacts were evaluated based on literature. Guide questions include (1) "How many *P. vannamei* have escaped?", (2) "Can escapees survive in the natural environment?", (3) "Can escapees establish a natural population?", (4) "What is the extent of the geographic spread of the alien pathogen, Taura syndrome virus (TSV)?", and (5) "Can *P. vannamei* potentially compete with native shrimp species?". The questions were answered and discussed based on literature, scientific details, reflections on personal experience, and their relevance to aquaculture of the *P. vannamei* in the Philippines. Conclusions were formulated based on the interpreted findings of this review, and recommendations were made for sustainable aquaculture of *P. vannamei* in the Philippines.
