billfish

Length-weight relationships for six species of billfishes in the central Pacific Ocean.

The large pelagic longline fisheries in the Indian Ocean date back to the 1950s, when the Asian fleets targeted mainly tropical tunas (Lee et al., 2005) and caught billfishes and sharks as bycatch.

"Nearly all the oceanic large fishes--that is tunas, billfishes and sharks--are currently being overfished so their populations are way below a pre-exploitation level and in some cases as low as less than 10 percent of their pre-exploitation level," said Dr.

Warm water tunas and billfishes are also more abundant, while Queensland gropers and tiger sharks are also visiting the region occasionally.

Prince (NOAA, Miami, FL) provided important literature and shared his extensive knowledge of tagging studies in billfishes.

This information may be practical in reducing the uncertainties in Billfish stock assessments and may offer valuable insight into management consideration of time-area closure regulations to reduce bycatch mortality of Atlantic billfishes.

Proceeding of the international workshop on age determination of oceanic pelagic fishes: tunas, billfishes, and sharks, U.

Records from fishing boats highlight four areas showing unusual diversity in sharks, tuna, billfishes, and other big predators, says Boris Worm of the Institute for Marine Science in Kiel, Germany.

"It is imperative that our nation and our fishing community around the world get out the message that the economic value of sportfishing and of healthy marlin stocks can equal or exceed that of the commercial fisheries aimed at maximizing pounds on the dock," said Peel, who is currently mounting a campaign to get the Caribbean nations to increase their presence at ICCAT and increase the pressure for proper conservation of billfishes. "If we can't convince the Taiwanese, Japanese, Korean, Chinese and European Union to take the conservation of blue marlin seriously, we will not see any recovery in the Atlantic in our lifetimes."

Studies on the relative effectiveness of hook types for billfishes have revealed that circle hooks offer a conservation benefit (reduced rates of deep hooking) while maintaining catch rates comparable to those with J hooks for both troll and longline fisheries (Serafy et al., 2009).

Istiophorid billfishes are highly migratory species that inhabit the tropical and subtropical, epipelagic waters of the world's oceans, a large, relatively homogeneous environment that lacks significant physical barriers and most species spawn over broad geographic regions during a protracted season (Nakamura, 1995).

Most research on Atlantic billfishes has focused on issues of stock structure, population abundance, and fishing mortality as part of stock assessments that, since 1994, have been performed every 2-4 years under the auspices of the International Commission for the Conservation of Atlantic Tunas (ICCAT).