42
G. J. Pierce and J. Portela
3.1 Introduction
Global marine fisheries are widely perceived to be in crisis. World capture production seems to have peaked, there is concern that we are ‘fishing down the food web’,
many fish stocks are evidently overexploited, it has been suggested that capture
fisheries will be extinct by the mid-twenty-first century, and even apparent success
stories like lobster fisheries in the US Gulf of Maine have a less palatable flip side
of ecological damage and vulnerability to disease outbreaks (Branch et al. 2010;
Worm et al. 2009; Hilborn 2012).
As many finfish stocks decline, increased attention has been focused on other
groups such as cephalopods (Caddy 1983). The cephalopods comprise the squid,
octopuses, cuttlefish (grouped together as the coleoids) and nautiloids. There are
about 800 living species although cephalopod taxonomy continues to be in a state
of flux as molecular genetics challenges traditional views of relationships between
species (Allcock 2010).
In 1983, the Food and Agriculture Organization (FAO) of the United Nations
issued Fisheries Technical Paper N° 231 (Caddy 1983), in which it was stated that
‘…except in a few ocean regions, they (cephalopods) are not subject to exploitation.
Most of the large industrial cephalopod fisheries are concentrated in the Northwest
and central Pacific, the northwest African coasts, the Mediterranean and the Northwest Atlantic.’ It was also said that ‘in the search for resources that can locally
support a high level of exploitation in the near future, cephalopods must occupy a
leading place’. This situation has unquestionably changed over the past 30 years.
Cephalopods are now highly valuable commercial fishery resources with annual
world catches reaching 4.3 million t in 2007 but decreasing to 3.6 million t in 2010,
according to FAO statistics (FAO 2011), having increased steadily from around
600,000 t in 1950 (Jereb and Roper 2010). Caddy and Rodhouse (1998) suggested
that this may be at least partly due to ecological replacement, with opportunistic
cephalopod species occupying niches vacated by overfished finfish stocks. However, Nigmatullin (2010) ascribed the increase mainly to the expansion of fishing
grounds, targeting new species and increasing fishing effort. Again as shown by
FAO data, since the 1980s the expansion has slowed down as all the main inshore
commercial stocks of cephalopods were exploited, and the past few years have
shown a decrease in total cephalopod landings. Indeed, there is evidence that many
coastal cephalopod stocks may have been overfished (notably in Asia: see FungeSmith et al. 2012).
Besides their importance for human consumption, cephalopods are useful research models not only in medical and biological research, due to their nervous
system and sense organs (Lee 1994; Koueta and Boucaud-Camou 1999), but also in
physiology, neuroscience, nutritional biochemistry, ageing, molecular biology and
immunology (Oestmann et al. 1997; Domingues et al. 2001).
Cephalopods are distributed throughout the world’s oceans and it is evident that
we are not yet exploiting cephalopods in many areas where they occur, especially far
from land (Fries 2010). Nigmatullin (2004, 2010) proposed that significant further
G. J. Pierce and J. Portela
3.1 Introduction
Global marine fisheries are widely perceived to be in crisis. World capture production seems to have peaked, there is concern that we are ‘fishing down the food web’,
many fish stocks are evidently overexploited, it has been suggested that capture
fisheries will be extinct by the mid-twenty-first century, and even apparent success
stories like lobster fisheries in the US Gulf of Maine have a less palatable flip side
of ecological damage and vulnerability to disease outbreaks (Branch et al. 2010;
Worm et al. 2009; Hilborn 2012).
As many finfish stocks decline, increased attention has been focused on other
groups such as cephalopods (Caddy 1983). The cephalopods comprise the squid,
octopuses, cuttlefish (grouped together as the coleoids) and nautiloids. There are
about 800 living species although cephalopod taxonomy continues to be in a state
of flux as molecular genetics challenges traditional views of relationships between
species (Allcock 2010).
In 1983, the Food and Agriculture Organization (FAO) of the United Nations
issued Fisheries Technical Paper N° 231 (Caddy 1983), in which it was stated that
‘…except in a few ocean regions, they (cephalopods) are not subject to exploitation.
Most of the large industrial cephalopod fisheries are concentrated in the Northwest
and central Pacific, the northwest African coasts, the Mediterranean and the Northwest Atlantic.’ It was also said that ‘in the search for resources that can locally
support a high level of exploitation in the near future, cephalopods must occupy a
leading place’. This situation has unquestionably changed over the past 30 years.
Cephalopods are now highly valuable commercial fishery resources with annual
world catches reaching 4.3 million t in 2007 but decreasing to 3.6 million t in 2010,
according to FAO statistics (FAO 2011), having increased steadily from around
600,000 t in 1950 (Jereb and Roper 2010). Caddy and Rodhouse (1998) suggested
that this may be at least partly due to ecological replacement, with opportunistic
cephalopod species occupying niches vacated by overfished finfish stocks. However, Nigmatullin (2010) ascribed the increase mainly to the expansion of fishing
grounds, targeting new species and increasing fishing effort. Again as shown by
FAO data, since the 1980s the expansion has slowed down as all the main inshore
commercial stocks of cephalopods were exploited, and the past few years have
shown a decrease in total cephalopod landings. Indeed, there is evidence that many
coastal cephalopod stocks may have been overfished (notably in Asia: see FungeSmith et al. 2012).
Besides their importance for human consumption, cephalopods are useful research models not only in medical and biological research, due to their nervous
system and sense organs (Lee 1994; Koueta and Boucaud-Camou 1999), but also in
physiology, neuroscience, nutritional biochemistry, ageing, molecular biology and
immunology (Oestmann et al. 1997; Domingues et al. 2001).
Cephalopods are distributed throughout the world’s oceans and it is evident that
we are not yet exploiting cephalopods in many areas where they occur, especially far
from land (Fries 2010). Nigmatullin (2004, 2010) proposed that significant further