34
4 Management and Conservation of Marine Life
4.1 Fisheries
Some species of commercial value display fidelity to localized high-productivity frontal
regions. Once abundant prey patches are located, predators may remain in these discrete
regions for extended periods of time which ultimately leads to their spatial aggregation favoring fishing operations. Moreover, high densities of non-schooling species (e.g.
swordfish) may occur only where loose aggregations are formed for spawning or feeding, which frequently take place at fronts (Podestá et al. 1993). There is abundant literature supporting the association of longline fisheries directed to large pelagic predators
(e.g. tunas; swordfish; marlin) and fronts (Etnoyer et al. 2004; Lan et al. 2012; Andrade
2003). It is common practice in several pelagic fisheries to use satellite derived SST charts
to locate thermal fronts. This technology allows fishermen to choose the most profitable
areas to fish. Relationship between fronts and demersal fish fisheries are not so clear. In
the case of Icelandic cod it appears to be a well-established fact among fishermen that
regions of high temperature gradients (i.e. thermal fronts) tend to be indicators of fish
schools. It has been suggested that the food for cod, such as capelin, may aggregate in
thermal fronts; therefore it might be expected that the cod would tend to be found at such
fronts (Brynjarsdóttir and Stefánsson 2004). Several short-finned squids (Illex argentinus
from Patagonia; Todarodes pacificus from Japan; I. illecebrosus from the Northwestern
Atlantic) have been shown to be associated with frontal regions occurring between different water masses, and fishing fleets concentrate efforts on feeding or reproductive aggregations occurring at these fronts (Gong et al. 1993; Brodziak and Hendrickson
1998; Kiyofuji and Saitoh 2004; Powell et al. 2005; Waluda et al. 2008) (Fig. 4.1). Some
Fig. 4.1 Light generated
by jigging vessels fishing
Argentine short-fin squid
(Illex argentinus) concentrate
along the shelf-break front
in Patagonia on April 23,
2014 (Image generated
by Subprograma de
Sensoramiento Remoto—
INIDEP based on data
from NOAA http://www.
class.noaa.gov)
4 Management and Conservation of Marine Life
4.1 Fisheries
Some species of commercial value display fidelity to localized high-productivity frontal
regions. Once abundant prey patches are located, predators may remain in these discrete
regions for extended periods of time which ultimately leads to their spatial aggregation favoring fishing operations. Moreover, high densities of non-schooling species (e.g.
swordfish) may occur only where loose aggregations are formed for spawning or feeding, which frequently take place at fronts (Podestá et al. 1993). There is abundant literature supporting the association of longline fisheries directed to large pelagic predators
(e.g. tunas; swordfish; marlin) and fronts (Etnoyer et al. 2004; Lan et al. 2012; Andrade
2003). It is common practice in several pelagic fisheries to use satellite derived SST charts
to locate thermal fronts. This technology allows fishermen to choose the most profitable
areas to fish. Relationship between fronts and demersal fish fisheries are not so clear. In
the case of Icelandic cod it appears to be a well-established fact among fishermen that
regions of high temperature gradients (i.e. thermal fronts) tend to be indicators of fish
schools. It has been suggested that the food for cod, such as capelin, may aggregate in
thermal fronts; therefore it might be expected that the cod would tend to be found at such
fronts (Brynjarsdóttir and Stefánsson 2004). Several short-finned squids (Illex argentinus
from Patagonia; Todarodes pacificus from Japan; I. illecebrosus from the Northwestern
Atlantic) have been shown to be associated with frontal regions occurring between different water masses, and fishing fleets concentrate efforts on feeding or reproductive aggregations occurring at these fronts (Gong et al. 1993; Brodziak and Hendrickson
1998; Kiyofuji and Saitoh 2004; Powell et al. 2005; Waluda et al. 2008) (Fig. 4.1). Some
Fig. 4.1 Light generated
by jigging vessels fishing
Argentine short-fin squid
(Illex argentinus) concentrate
along the shelf-break front
in Patagonia on April 23,
2014 (Image generated
by Subprograma de
Sensoramiento Remoto—
INIDEP based on data
from NOAA http://www.
class.noaa.gov)