jueves, 18 de agosto de 2011

Sport fishing boats and Cetaceans in the Strait of Gibraltar

Game fishing for Tuna - Fishing charter in Spain - is an issue of concern because of direct injuries from the hooks pulled behind the boats. On some occasions these injuries are caused by disrespect for cetaceans, by boats that cross their swimming direction or that drive into groups of cetaceans, even as they swim beside whale watching boats. One reason is that some believe the tuna swim underneath the dolphins. This might be true in the Pacific Ocean, but it’s not in the Strait of Gibraltar. The migration of tuna between the Atlantic and Mediterranean is not related to the permanent presence of cetaceans in the Strait of Gibraltar.
The following photos show injuries caused by fishing gear. Some of them may have been caused by illegal drift nets, but most have been infringed by the lines pulled by private tuna game-fishing boats. When the line starts to cut from the trailing edge of the dorsal fin and the whale eventually dives, only a small front portion of the dorsal fin is saved. We observe most of the fresh injuries during the tuna fishing season, when up to 40 sport boats can be seen at once in the Strait.

Whale watching
In 2007 whale watching guidelines were implemented in Spain, but some captains have not lost there old habits. They argue that the whales are habituated to ship traffic and can be approached without much disturbance, but it makes a great difference if a big vessel crosses straight or if a boat follows the whales, disrupting their natural behaviour for a longer period of time. It is even worse when one boat calls the other by radio, causing a continuous presence at one group of animals. The following photos show a Pilot Whale with a deep cut from a propeller, caused by a stopped boat (since a driving boat would have caused multiple cuts). Unfortunately it cannot be excluded that it was originated by the propeller of a whale watching boat.

Mitigation Measures
In order to protect and conserve the cetaceans of the Strait of Gibraltar fishing, the stress factors described should be reduced as much as possible.
Private boats: They should be informed of the different kind of correlation that exists between the presence of dolphins and tuna in The Strait and in the Pacific Ocean. They should also comply with whale watching regulations.
Whale watching: Compliance with whale watching regulations should be improved (see summary of regulations below)

REAL DECRETO 1727/2007, de 21 de diciembre, por el que se establecen medidas de protección de los cetáceos.
ANEXO II
1. General code of conduct while observing cetaceans inside the previously defined mobile protection space:
A. It is prohibited to use sonar systems to detect cetaceans or to push them to the surface.
B. Ships must move at constant speed of 4 kn. or as slow as the slowest animal in the group, but not inside the “prohibited zone”, where a different code of conduct specified at section 2 of this appendix must be applied. Once finished, the ships must continue at that constant speed until having left the mobile protection space.
C. The approach must be done converging slowly from one side at an angle of 30º to their swimming direction, never from the front, from behind nor perpendicular to their trajectory. While observing the cetaceans the ship must navigate parallel, without sudden changes of speed and direction.
D. Boats approaching simultaneously must coordinate it by radio, in order to reduce the disturbance as much as possible.
E. If the engine was stopped and is started again, it must be kept at empty running for at least 1 minute. Every change of the revolutions of the engine must be done smoothly.
F. Driving backwards is only allowed to avoid collisions with other ships or cetaceans.
G. Never drive in circles around the cetaceans.
H. If cetaceans approach diving people, the latter must avoid interacting with them and leave the area as soon as possible safety allows.
2. General code of conduct while observing cetaceans inside the different sections of the previously defined mobile protection space.
In the Prohibited Zone:
A. Permission to navigate only under emergency circumstances.
B. If cetaceans emerge suddenly at less than 60 m from the boat, the propeller must be stopped.
C. As long as animals remain at less then 60 m from the boat, the propeller must remain stopped and can only be reengaged some minutes after departure of the animals. The navigations must be started smoothly, taking especial care in making sure no animals hang about the propeller.
D. If the emerging animals are dolphins or porpoises, it is allowed to continue with constant prudent speed, maintaining the initial speed.
E. Sonar must stay switched off.
In the Zone of temporary stop only:
A. Prohibited if lonely calf-adult pairs or lonely calves are present.
B. A maximum of two ships are allowed at once.
In the zone of special care:
A maximum of two ships are allowed to stay waiting if two other ships are already inside the Zone of Temporary Stop and they have to wait until the first arrivers leave. Ships must coordinate movements through radio.
In the Aerial Zone:
It is prohibited to stay.
In the Submarine Zone:
It is prohibited to stay.