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Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN

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Treaty Organization (NATO) caused a 1996 mass str<strong>and</strong>ing<br />

of Cuvier’s beaked whales (Ziphius cavirostris) in the<br />

Kyparissiakos Gulf, western Greece (Frantzis 1998), led to<br />

a series of NATO-funded meetings, experiments, <strong>and</strong> dedicated<br />

research cruises, with assurances that mitigation procedures<br />

<strong>and</strong> policies would be developed <strong>and</strong> implemented.<br />

Similarly, the mass mortality of Cuvier’s, Blainville’s<br />

(Mesoplodon densirostris), <strong>and</strong> Gervais’ beaked whales (M.<br />

europaeus), <strong>and</strong> two minke whales, in the Bahamas in<br />

March 2000 resulted in a flurry of efforts to investigate the<br />

link with military activities (Balcomb <strong>and</strong> Claridge 2001;<br />

Anon. 2001).<br />

Reducing <strong>and</strong> mitigating the effects of<br />

coastal development<br />

The degradation of coastal <strong>and</strong> estuarine environments continues<br />

at a staggering rate over much of the planet, <strong>and</strong><br />

cetaceans are merely one group in a long list of organisms<br />

that are losing habitat as a result. This problem, like so many<br />

others, ultimately boils down to the fact that the human<br />

population is increasing in size, <strong>and</strong> hence, our capacity to<br />

consume the earth’s resources is growing at an alarming<br />

rate. L<strong>and</strong> “reclamation,” deforestation of mangroves, <strong>and</strong><br />

harbor development represent a few of the ways in which we<br />

rush to exploit, or transform, fragile <strong>and</strong> undervalued biological<br />

systems in the coastal zone.<br />

It is difficult to see a way forward, considering how<br />

powerful the economic <strong>and</strong> political forces behind unchecked<br />

development are. However, if there is to be any<br />

hope of slowing, <strong>and</strong> perhaps even reversing, current trends,<br />

it must reside in our ability to force governments to plan <strong>and</strong><br />

regulate development in the coastal zone. The public must<br />

insist on a transparent <strong>and</strong> rigorous process of environmental<br />

impact review, assessment, <strong>and</strong> mitigation. For their<br />

part, cetacean biologists need to improve our underst<strong>and</strong>ing<br />

of coastal ecology <strong>and</strong> convey our findings to a wide audience.<br />

Reducing the effects of water<br />

development on freshwaterdependent<br />

cetaceans<br />

Freshwater cetaceans need to be considered in the assessment<br />

of impacts of water development projects. In virtually<br />

every case, the preferred option, from a conservation perspective,<br />

is to refrain from interfering with the natural flow<br />

regime <strong>and</strong> to avoid constructing barriers to animal (<strong>and</strong><br />

sediment) movement. However, given that further construction<br />

of dams, barrages, embankments, <strong>and</strong> other<br />

28<br />

obstructions to natural flow is inevitable, the immediate<br />

goal must be to manage, rather than completely stop, water<br />

development. Toward this end, the following principles <strong>and</strong><br />

guidelines were adopted at a 1997 CSG-sponsored workshop<br />

on water development <strong>and</strong> freshwater cetaceans<br />

(Smith <strong>and</strong> Reeves 2000b):<br />

� Freshwater cetaceans require sufficient year-round<br />

water flow to move freely between deep pools, to<br />

forage successfully, <strong>and</strong> to carry out activities that<br />

ensure reproductive success <strong>and</strong> recruitment into the<br />

breeding population.<br />

� The siting <strong>and</strong> operation of dams, barrages, <strong>and</strong> other<br />

gated structures in waterways must take into account<br />

the risks associated with barrier effects.<br />

� If built, dams should be located in upstream tributaries<br />

or, as a last resort, in the main river channel immediately<br />

upstream of confluences.<br />

� Large daily fluctuations in flow should be avoided.<br />

� Equilibrium between sediment erosion <strong>and</strong> deposition<br />

is necessary to maintain essential habitat features, <strong>and</strong><br />

this can often be accomplished by managing flow<br />

releases according to environmental criteria.<br />

� Access to floodplains should be preserved to ensure<br />

natural spawning <strong>and</strong> rearing habitat for cetacean<br />

prey.<br />

� Fishways should be considered for mitigating the barrier<br />

effects of dams. However, they must accommodate<br />

the specific needs of species within the<br />

context of the post-development environment <strong>and</strong> be<br />

designed so that their operation can be modified in the<br />

light of experimentation <strong>and</strong> monitoring.<br />

� Information on the pre-development ecological conditions<br />

of a river is essential for evaluating the success<br />

of mitigation efforts <strong>and</strong> for informing future development<br />

decisions.<br />

� Post-development empirical studies are needed to<br />

monitor the operational aspects of projects as well as<br />

the effects on upstream <strong>and</strong> downstream populations<br />

of cetaceans <strong>and</strong> their habitat.<br />

� Cumulative <strong>and</strong> synergistic impacts of multiple developments<br />

should be considered in assessments of<br />

environmental impact. In cases where the predicted<br />

impacts are judged to be severe <strong>and</strong> cannot be reduced<br />

to acceptable levels, the option of not constructing the<br />

project should be considered.<br />

It is important to recognize that the habitat of some marine<br />

cetaceans is strongly influenced by freshwater inputs. The<br />

needs of these freshwater-dependent, estuarine species (e.g.,<br />

Indo-Pacific hump-backed dolphin, Irrawaddy dolphin,<br />

franciscana) should be considered when assessing the<br />

downstream effects of diversion or impoundment schemes.

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