Sustainable Management of the Shark Resources of Atlantic Ocean Socioeconomic and Biological Characteristics of the Fishery

Sustainable Management of the Shark Resources of Atlantic Ocean Socioeconomic and Biological Characteristics of the Fishery

Chapter One of Sustainable Management of the Shark Resources of Atlantic Ocean Socioeconomic and Biological Characteristics of the Fishery

INTRODUCTION

BACKGROUND TO THE STUDY 

Not only are sharks among the ocean’s top predators and vital to the natural balance of marine ecosystems, they are also a valuable recreational species and food source (Scott & Scott, 1988). To help protect these important marine species, the many countries especially the advanced countries has some of the strongest shark management measures worldwide (DFO, 2000). There are a variety of resources related to sharks and their management throughout the Atlantic Ocean. There are several shark species found in the Atlantic ocean.
According to Boyle et al (1998), the blue shark is the most common and commercially valuable of these species, however other species such as the Mako, Greenland, Basking, and Porbeagle sharks, have been assessed for their commercial significance in recent years. The blue shark (Pronace glauca) is a large pelagic species with a long slender body, narrow head, five-gill slits, large eyes, a pointed snout, and long scythe-like pectoral fins. It has an elongated, sickle shaped caudal fin (tail), which enables it to be a powerful and fast swimmer. This species has a characteristic blue colour on the upper surface shading to a pure white on its abdomen. The blue shark is one of the fastest growing species of shark, ranging in size from1.8 to 3.8 m and weighing 29 to 55 kg. The life span of blue sharks is unknown but it is estimated that they can reach a maximum age of 20 years. Pronace. glauca is found in both inshore and offshore waters in the Atlantic Ocean, as well as adjoining seas, approximately 500 N to 500 S. The blue shark is the most widely distributed of all shark species. The blue shark prefers near surface temperate water, ranging from 13 to 180C, but can tolerate from 7 to 270C. The blue shark is an opportunistic feeder but prefers feeding on small pelagic schooling fish such as herring, mackerel, sardine and anchovy. The only natural predators of the blue shark are other larger shark species (Boyle et al, 1998). Sharks have been exploited in the Atlantic ocean since the early 1960s, however the majority of shark landings for Atlantic ocean have been by-catch in established fisheries such as longline swordfish and other groundfish fixed gear fisheries. Closure and reductions in many of the traditional groundfish fisheries has resulted in more fishers interested in developing a target fishery for pelagic shark species, particularly for porbeagle, short-fin mako, and the blue shark and to a lesser extent the basking and Greenland sharks (Campana et al, 2001).
Total landings of shark for Atlantic ocean averaged 44 metric tones (mt) from 1995 to 2002, with 1998 recording the highest value. Prior to a formal shark fishery in Atlantic ocean, it was thought shark resources of the region were underutilized. Shark species are relatively slow growing, long-living organisms with low reproductive rates, making them highly susceptible to over-harvesting. Therefore, numerous shark fisheries throughout the world have collapsed after a short period of exploitation. Prior to 1994, access to shark resources in Atlantic ocean was not restricted and no formal management measures existed. In 1995, an interim management plan was introduced and by 1997, a multi-year management was initiated (1997-1999) and updated in 2000-2001. Under these new fishery regulations only vessels over 65 feet are allowed to participate, harvesting gear is limited to handline, longline or rod and reel, no by-catch of tunas or swordfish are allowed and all landing are monitored by appropriate fisheries authorities (Campana et al, 2001).
Landed shark must be handled carefully and quickly in order to preserve product quality. Immediately after capture, the shark must be bled by cutting off the head and tail portion, then gutted, washed, and packed in ice and slush solution (Subasinghe, 1992). When properly handled and iced, shark will remain fresh for 7 to 10 days. There are several products made from shark including oil, whole dressed shark, fresh or frozen steak, leather tanning products and various types of medicine; however the most valuable product is shark fins, which are one of the most expensive fish products in the world (DFO, 2000).

STATEMENT OF THE PROBLEM 

For a sustainable management, future development of the shark resources and fishery in the Atlantic ocean will require more research into species distribution and biology to determine abundance and develop management measures for sustainable harvest. In addition, the industry requires processors interested in purchasing and processing whole shark, a consistent supply of top quality shark meat, and greater marketing effort directed at consumer specification and finding new markets niches.