Sanctuaire Agoa

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Chapter 3. SITE DESCRIPTION

f - Impacts and threats affecting the area

Impacts and threats within the area


Impact and threats level Evolution In the short term Evolution In the long term Species affected Habitats affected Description / comments
Exploitation of natural ressources: Fishing significant stable stable Megaptera novaeangliae Balaenoptera edeni Balaenoptera acurostrata Physeter macrocephalus Kogia breviceps Kogia simus Stenella attenuata Stenella clymene Stenella coeruleoalba Stenella frontalis Stenella longirostris Steno bredanensis Feresa attenuata Globicephala macrorhynchus Grampus griseus Lagenodelphis hosei Orcinus orca Peponocephala electra Pseudorca crassidens Tursiop truncatus Ziphius cavirostris Mesoplodon densirostris Mesoplodon europaeus Habitat degradation by waste and discarded fishing gear These wastes also have impacts on marine life, habitats and marine mammals in two ways, especially if they are made of synthetic material non-degradable: - Entanglement, the process by which animals and their habitats are entangled or trapped, - Ingestion, with intentional or accidental ingestion of discarded or lost fishing gear. In the past, drift nets not properly handled were the main causes of accidental catches. Their ban in 1992 certainly contributed to the reduction of “ghost fishing”. However, the use of gillnets is also particularly harmful to migratory species. If a gillnet is abandoned or lost, it can continue to fish on its own for months - and sometimes years - indiscriminately killing. The most complete study on the impact of marine debris in general, including fishing gear, is probably the one conducted by Laist (1997). In general, the entanglement is considered as a cause of death much more likely that the ingestion. In all documented accounts of entanglements of sea turtles, seabirds, marine mammals, and fish or crustaceans, the most significant source of these incidents is a fishing gear (longlines in monofilament nets and ropes). The main source of this material is apparently the commercial fishery, although commercial vessels and recreational fishing may also contribute. As such, the campaign “ Exocet-Antilles” conducted in February-March 2008 by the French Marine Protected Areas Agency, under the management of the Centre for Research on Marine Mammals of the University of La Rochelle, has made a modeling result of anthropogenic activities throughout the EEZ of the French Antilles in the sanctuary AGOA. Predictions for the distributions of fishing buoys, fishing boats, floating waste and sailboats are shown in Figure 17. The resulting predictions show that all human activities (fishing and boating) is concentrated around the islands, while the waste is most abundant west of the West Indies, and perhaps also in deep zone, as shown the area northeast of the map. The predictions of the positions of fishing buoys indicate the extensive use of coastal waters including the islands of Guadeloupe and Saint Martin and Saint Barthelemy. The distribution of the latter coincides only partially with bottom gears such FADs (fish concentration devices), gill nets and traps that can be located up beyond the insular shelf (Guillou & Lagin. 1997).
Exploitation of natural ressources: Agriculture significant stable stable - Reproductive capacities and immune system could be affected and could lead to the death of the animal, tumors ... - Intoxication (hydrocarbons) - Physiological dysfunction (nervous system) - Intoxication newborns - Endocrine disruption
Exploitation of natural ressources: Tourism significant stable increase - Desertion of habitats
Exploitation of natural ressources: Industry limited stable stable - Reproductive capacities and immune system could be affected and could lead to the death of the animal, tumors ... - Intoxication (hydrocarbons) - Physiological dysfunction (nervous system) - Intoxication newborns - Endocrine disruption
Exploitation of natural ressources: Forest products limited stable stable unknown
Increased population significant increase increase Loss of habitat, pollution...
Invasive alien species significant increase increase Steno bredanensis Tursiop truncatus The "lionfish" Pterois volitans has invaded the waters of the French Antilles. It is recognized that in the Caribbean, he grew to 0.5mm / d and can reach 48cm (35cm max only in the Pacific). In Mexico, in areas already infested, the density of lionfish reached 100 to 150 lionfish per hectare, and over 400 individuals per hectare in some places in the Bahamas. A recent study showed that 80 lionfish consume about 1 km of reefs around 50,000 fish / year. Its diet varies, but about 50 fish species are concerned (including commercial fish and coral), and 20 species of crustaceans. The food source for marine mammals subservient to the coastal environment is thereby greatly threatened.
Pollution significant stable stable Megaptera novaeangliae Balaenoptera edeni Balaenoptera acurostrata Physeter macrocephalus Kogia breviceps Kogia simus Stenella attenuata Stenella clymene Stenella coeruleoalba Stenella frontalis Stenella longirostris Steno bredanensis Feresa attenuata Globicephala macrorhynchus Grampus griseus Lagenodelphis hosei Orcinus orca Peponocephala electra Pseudorca crassidens Tursiop truncatus Ziphius cavirostris Mesoplodon densirostris Mesoplodon europaeus • Oil and chemical pollution Although oil spills are regularly observed within the EEZ of French West Indies (6 cases over the period 2008-2009) and even if the phenomenon is not negligible (the oil spills can affect marine mammals directly by causing poisoning and chronic irritation of sensitive tissues, or by impregnating and suffocating species) the total quantity of pollutants from discharges and possible "oil spill" is insignificant compared to the pollution caused by domestic sewage, the industrial discharges, urban runoff, spills, dumping operations, mining, pesticides, agricultural fertilizers and waste heat sources that can potentially alter ecosystems and feeding areas, calving rates and rest of marine mammals. Some substances bioaccumulated by plants, marine organisms including marine mammals are known to be toxic, carcinogenic or teratogenic or inducing death, sterility, malformations, etc. ... This is the case of benzo [a] pyrene (class of polycyclic aromatic hydrocarbons), polychlorinated biphenyls, endocrine disruptors, lead and other metals in the environment due to pollution. Bioaccumulation occurs through food, and all through the food web. The more the food chain is important, the greater is the accumulation and the greater are the adverse effects. Predators such as toothed whales, located in the terminal portions of food chains are particularly vulnerable to this type of pollution that can impair their ability to reproduce and disease resistance. It is difficult today - to date no studies in the French West Indies - to determine precisely the effects of pollutants on marine mammal populations that frequent the sanctuary. Waste-water, contaminated by various endocrine disruptors (eg.: Xeno-estrogens or drugs) are treated through the waste-water treatment plants (WWTP). In these treatments, chemical compounds can be degraded completely or partially, creating sewage sludge on their absorption by suspended particles. Various factors such as type of treatment or the residence time may influence the efficiency of removal of pollutants through STEP. The problem stems from the inefficiency of STEP to retain certain substances, it follows that the latter are found in the treated water which will then contaminate surface water. In Martinique and Guadeloupe, the use of chlordecone used as an insecticide, especially against the weevil in banana plantations from 1979 to 1993 resulted in contamination of 40 to 45% of agricultural parcels (Asconit, 2005). It was used until the years 2005-2007. Its use has polluted the whole Antillean ecosystem in which we find concentrations greater than 100 times the norm, especially in water and soil. Research conducted by IFREMER showed that some of the coastal marine environments are contaminated with organochlorine, but no data exists on the potential contamination of cetaceans and the amplification of the toxic effects of some solvents (carbon tetrachloride , chloroform and dichloromethane, associated with chlordecone. In fact, the presence of fish and contaminated areas in the waters of Guadeloupe and Martinique may have a direct influence on the health of marine mammals that frequent these areas particularly for food.
Other significant not specified not specified Megaptera novaeangliae Balaenoptera edeni Balaenoptera acurostrata Physeter macrocephalus Kogia breviceps Kogia simus Stenella attenuata Stenella clymene Stenella coeruleoalba Stenella frontalis Stenella longirostris Steno bredanensis Feresa attenuata Globicephala macrorhynchus Grampus griseus Lagenodelphis hosei Orcinus orca Peponocephala electra Pseudorca crassidens Tursiop truncatus Ziphius cavirostris Mesoplodon densirostris Mesoplodon europaeus Marine environment near the coats and offshore Noise disturbance. We must distinguish in the different noise disturbance from human activities in the ocean: - The point-source emission of high intensity at low and medium frequency (associated with seismic surveys, underwater explosions, implementation of sediment profilers or military sonar), - The "ambient noise", continuous and low-frequency, emitted mainly by shipping, - The potential impact of offshore wind fields represents another kind of emerging threat. For cetaceans which have a strong dependency relationship with the acoustic information (foraging, navigation, social interactions), all reductions of listening skills, whether by noise or physical alteration of the inner ear, can compromise the survival of individuals and populations. It is recognized that the peaks of noise pollution (high intensity low frequency) are a major cause of stranding of cetaceans. The impacts of anthropogenic noise on cetaceans are multiple. Here we resume those discussed in the management plan of the Pelagos sanctuary for marine mammals (Tilot, 2004): - Physical impact : body tissue and auditory system damaged - Perceptive impact : make difficult to communicate with other of their kind, mask other important biological sounds, interference with listening skills, adaptive shift vocalizations - Behavioral impact: interruption of normal behavior, behavior change (less efficient), travel outside the area of noise. - Chronic stress - Indirect effects: depletion of preys, inciting an addiction to sounds The maritime traffic and the risk of collision Disturbance Marine traffic in the area of ??the sanctuary AGOA can be a threat for the cetacean at critical times (feeding, breeding, resting, socializing and migration). The stress can cause changes in behavior and physiology with a lower reproductive rate, decreased lactation, reduced disease resistance (David, 2002) ... These repeated disturbances may also have long term consequences on marine mammals and in particular the movement of animals in areas less favorables to their lifestyle. The collision Collisions are a recognized cause of cetacean mortality in the world, but there is little information about it. It is therefore difficult to assess the importance and impact of collisions on cetacean populations. As part of a specific research on this issue, Laist et al (2001) shows that: - Any type of boat or craft may encounter cetaceans - The most lethal and serious injuries are caused by vessels over 80 m, and / or vessels up to a speed exceeding 13 knots - Collisions are responsible for many cetacean strandings since the fifties, when the speed and number of boats in action exceeded a certain threshold. All species can be potentially impacted by shipping, but at different levels depending on several parameters. The primary factors are the intensity and frequency of exposure to disturbance, and the biological importance of the period. We must also consider the individual characteristics of animals and the habitat characteristics. Small dolphins, fastest and strongest, are generally less affected by the boats. However, exceptional conditions, such as unusual concentration of boats in confined and shallow, could significantly increase the risks and collisions (Wells and Scott 1997 in David 2002). This risk is poorly documented, because little data exist on the main maritime routes used by ships in the French Antilles. AIS (Automatic Identification System) phased in during 2011 by the CROSS will know more precisely the maritime traffic in the Caribbean. Whale watching Today, there are still no regulations concerning the activity of whale watching in the waters under French jurisdiction. This is necessary because Martinique is facing a recent development of whale watching, rapid and uncontrolled, potentially detrimental to the well being and survival of animals observed, especially as the observation mainly concerns some dolphin populations ( Stenella attenuata, Trusiops truncatus Lagenodelphis hosei). In Guadeloupe, a charter of good practice was proposed in 2000 and signed in 2002 by institutional management (Regional Council, National Park, Council of Bouillante and DIREN) and professionals. For both islands, the activity is practiced in the leeward coast. In the Northern Islands, St. Martin and St. Barts, there is not yet commercial enterprises whose main activity is the observation of marine mammals. The whale watching activities,but also the recreational craft, sporting competitions or research can cause disturbance: the observation of whales and dolphins that often occurs during periods of breeding or resting, during which animals are more sensitive, can induce stress and reducing the rest, which cause a decrease in reproductive rates and increased mortality. Eventually, these repeated interactions and performed poorly may cause the flight of animals to other sites.

Impacts and threats around the area


Impact and threats Level Evolution In the short term Evolution In the long term Species affected Habitats affected Description / comments
Exploitation of natural ressources: Fishing significant unknown unknown unknown
Exploitation of natural ressources: Agriculture significant unknown unknown unknown
Exploitation of natural ressources: Tourism significant increase increase unknown
Exploitation of natural ressources: Industry significant unknown unknown unknown
Exploitation of natural ressources: Forest products limited unknown unknown unknown
Increased population significant increase increase unknown
Invasive alien species significant increase increase unknown
Pollution significant unknown unknown unknown
Other significant not specified not specified Megaptera novaeangliae Balaenoptera edeni Balaenoptera acurostrata Physeter macrocephalus Kogia breviceps Kogia simus Stenella attenuata Stenella clymene Stenella coeruleoalba Stenella frontalis Stenella longirostris Steno bredanensis Feresa attenuata Globicephala macrorhynchus Grampus griseus Lagenodelphis hosei Orcinus orca Peponocephala electra Pseudorca crassidens Tursiop truncatus Ziphius cavirostris Mesoplodon densirostris Mesoplodon europaeus Noise disturbance We must distinguish in the different noise disturbance from human activities in the ocean: - The point-source emission of high intensity at low and medium frequency (associated with seismic surveys, underwater explosions, implementation of sediment profilers or military sonar), - The "ambient noise", continuous and low frequency, emitted mainly by shipping, - The potential impact of offshore wind fields represents another kind of emerging threat. For cetaceans which have a strong dependency relationship with the acoustic information (foraging, navigation, social interactions), all reductions of listening skills, whether by noise or physical alteration of the inner ear, can compromise the survival of individuals and populations. It is recognized that the peaks of noise pollution (high intensity low frequency) are a major cause of stranding of cetaceans. The impacts of anthropogenic noise on cetaceans are multiple. Here we resume those discussed in the management plan of the Pelagos sanctuary for marine mammals (Tilot, 2004): - Physical impact : body tissue and auditory system damaged - Perceptive impact : make difficult to communicate with other of their kind, mask other important biological sounds, interference with listening skills, adaptive shift vocalizations - Behavioral impact: interruption of normal behavior, behavior change (less efficient), travel outside the area of noise. - Chronic stress - Indirect effects: depletion of preys, inciting an addiction to sounds