683
length (or biological maturity and reproduction stage) are frequently captured as
bycatch, affecting recruitment and resulting in a reduction of stocks (Rueda and
Defeo 2003).
20.5.2 Fishery technology
Actually, nearly 7 million tons of incidental catches are annually produced around
the world, which corresponds to approximately 8% of total marine catches (Eayrs
2007; FAO 2008). In this context, usually, the incidental catches are recorded as
bycatch. These species are not the target of the fishery activity but are opportunely
caught, and can be used to generate extra income for fishers or simply are discarded
back into the environment (Alverson et al. 1994; Graça-Lopes et al. 2002; Branco
and Verani 2006). In most commercial fisheries, bycatch generation has emerged as
a serious concern. Most non-target species caught returned to the sea already dead
(Gillett 2008), and therefore incapable of continuing replenishing their particular
stock. This scenario can be worst if we consider that most of the bycatches consist
of juvenile fishes (Haimovici and Mendonça 1996; Kelleher 2005; Branco and
Verani 2006), or fish that are important food resources to larger and commercially
important species.
Faced with this problem, many countries have been adopted several environmental regulation to minimize bycatch. For that reason, in the last two decades, technological modifications in fishing gears have emerged as a complementary fisheries
management strategy to help overcome this problems in the continuation of this
activity. These modifications are known worldwide as bycatch reduction devices
(BRDs) (Broadhurst et al. 2006, 2012). The BRDs are technological modifications
designed primarily to the bycatch exclusion. In this approach, the researchers, based
on local knowledge of the fishery, fishing method and behavior of local catches,
propose some technological alterations to increase the selectivity of the fishing gear.
BRDs have been shown to be an important management strategy in several parts of
the world, due to its lower cost compared to traditional, coercive, fishing rights
monitoring methods adopted by the governmental and non-governmental organizations (Campbell and Cornwell 2008). Such options are also common in attempts to
guarantee reduction of bycatch of species of conservation concern, as marine turtles
[exists at the cod end of trawl nets – TED (turtle excluder device)] and marine birds
(circular hooks) (Werner et al. 2006).
In South America, experiments with technological changes in fishing gear are
still incipient. In the southern Brazilian region, the Fisheries Science and Technology
Group (TECPESCA) at the Santa Catarina State University (Brazil) have evaluated
some alternative solutions for shrimp trawls. In this region, the bottom trawls are
economically relevant although they can contribute to environmental impacts in
coastal regions. According to Branco and Verani (2006), for each kg of shrimp, this
fishing method caught 19 kg of bycatch. To minimize bycatch generation, one of the
technological approaches proposed by the group was the fisheye at the cod-end of
20 How Can Accurate Landing Stats Help in Designing Better Fisheries…
length (or biological maturity and reproduction stage) are frequently captured as
bycatch, affecting recruitment and resulting in a reduction of stocks (Rueda and
Defeo 2003).
20.5.2 Fishery technology
Actually, nearly 7 million tons of incidental catches are annually produced around
the world, which corresponds to approximately 8% of total marine catches (Eayrs
2007; FAO 2008). In this context, usually, the incidental catches are recorded as
bycatch. These species are not the target of the fishery activity but are opportunely
caught, and can be used to generate extra income for fishers or simply are discarded
back into the environment (Alverson et al. 1994; Graça-Lopes et al. 2002; Branco
and Verani 2006). In most commercial fisheries, bycatch generation has emerged as
a serious concern. Most non-target species caught returned to the sea already dead
(Gillett 2008), and therefore incapable of continuing replenishing their particular
stock. This scenario can be worst if we consider that most of the bycatches consist
of juvenile fishes (Haimovici and Mendonça 1996; Kelleher 2005; Branco and
Verani 2006), or fish that are important food resources to larger and commercially
important species.
Faced with this problem, many countries have been adopted several environmental regulation to minimize bycatch. For that reason, in the last two decades, technological modifications in fishing gears have emerged as a complementary fisheries
management strategy to help overcome this problems in the continuation of this
activity. These modifications are known worldwide as bycatch reduction devices
(BRDs) (Broadhurst et al. 2006, 2012). The BRDs are technological modifications
designed primarily to the bycatch exclusion. In this approach, the researchers, based
on local knowledge of the fishery, fishing method and behavior of local catches,
propose some technological alterations to increase the selectivity of the fishing gear.
BRDs have been shown to be an important management strategy in several parts of
the world, due to its lower cost compared to traditional, coercive, fishing rights
monitoring methods adopted by the governmental and non-governmental organizations (Campbell and Cornwell 2008). Such options are also common in attempts to
guarantee reduction of bycatch of species of conservation concern, as marine turtles
[exists at the cod end of trawl nets – TED (turtle excluder device)] and marine birds
(circular hooks) (Werner et al. 2006).
In South America, experiments with technological changes in fishing gear are
still incipient. In the southern Brazilian region, the Fisheries Science and Technology
Group (TECPESCA) at the Santa Catarina State University (Brazil) have evaluated
some alternative solutions for shrimp trawls. In this region, the bottom trawls are
economically relevant although they can contribute to environmental impacts in
coastal regions. According to Branco and Verani (2006), for each kg of shrimp, this
fishing method caught 19 kg of bycatch. To minimize bycatch generation, one of the
technological approaches proposed by the group was the fisheye at the cod-end of
20 How Can Accurate Landing Stats Help in Designing Better Fisheries…