688
20.5.5 Human impacts
Another problem for fishery science is that human impacts that lead to environmental degradation were, and still are, neglected as possible causes of fish stocks collapse. Human impacts derived from unplanned urban settlements, unsustainable
land use and industries/domestic effluents are the main causes of habitat loss and/or
degradation (Figs. 20.6, 20.11, 20.12, 20.13, 20.14, 20.16, and Table 20.1). This is
especially pronounced in areas around estuaries, where shipping ports, cities, agriculture and aquaculture cause damages to fisheries production and therefore the
exportation of biomass from regional seas (Lotze et al. 2006; Dallas and Barnard
2009; Barletta et al. 2016).
Mangrove deforestation for whatever reasons has severely reduced habitat for
the development of estuarine resources, what reduces fish stocks for local communities and beyond, since estuarine fish are sold elsewhere to generate income and
supply distant markets. In the Cayapas-Mataje delta in Esmeraldas Province
(Ecuador/Colombia border), at least 6000 inhabitants directly rely on mangrove
resources for living (Ocampo-Thomason 2006). Artisanal fishing and arc-shells
picking (Anadara tuberculosa, A. similis and A. grandis) are the main economic
activities (Ocampo-Thomason 2006). However, changes such as African palm culture and commercial shrimp farming are having an impact on the mangrove ecosystem. Construction of shrimp farms has led to the destruction of arc-shells recruiting
and living grounds and damage to agricultural land (Ocampo-Thomason 2006).
Traditional communities responded to these changes by creating new management strategies agreed among political, ecological and social organizations. Two
movements came together in the north of Esmeraldas to defend the mangrove areas,
the Fundación para la Defensa Ecológica in 1989 and the Black Communities
Process. After 5 years of mobilizations and campaigns, the Ecuadorian government
granted the area status of ecological reserve, the Ecological Mangrove Reserve
Cayapas-Mataje (Ocampo-Thomason 2006). It led to the implementation of a novel
practice called ‘custodias’, a piece of land protected by recognized community
leader who retains traditional knowledge in resource management. It has been calculated that 98% of illegal mangrove removal has stopped, confirming the potential
success of this aproach (Ocampo-Thomason 2006).
Another issue for estuarine ecological processes is the lack of basic sanitation
(sewage treatment), often the worst concern in estuarine pollution and degradation
(Costa and Barletta 2016). High loads of solid wastes are also contaminating estuaries increasing the risk of higher plastic debris ingestion (macro or micro) by estuarine fauna (Lima et al. 2014; Ferreira et al. 2016) (Table 20.1). Wastewater from
household, industries and farms generate high amounts of pesticides (POPs) and
heavy metal that directly affect water and aquatic biomass quality (Costa et al. 2009;
Barletta et al. 2012; Silva-Cavalcanti et al. 2016). Shellfish species, for example,
depend on good water and suspended particulate organic matter quality to generate
meat safe for consumption. Efforts to better use of surrounding land and treatment
of effluents are important in determining shellfish survival, meat quality and livelihoods (Barletta and Costa 2009).
M. Barletta et al.
20.5.5 Human impacts
Another problem for fishery science is that human impacts that lead to environmental degradation were, and still are, neglected as possible causes of fish stocks collapse. Human impacts derived from unplanned urban settlements, unsustainable
land use and industries/domestic effluents are the main causes of habitat loss and/or
degradation (Figs. 20.6, 20.11, 20.12, 20.13, 20.14, 20.16, and Table 20.1). This is
especially pronounced in areas around estuaries, where shipping ports, cities, agriculture and aquaculture cause damages to fisheries production and therefore the
exportation of biomass from regional seas (Lotze et al. 2006; Dallas and Barnard
2009; Barletta et al. 2016).
Mangrove deforestation for whatever reasons has severely reduced habitat for
the development of estuarine resources, what reduces fish stocks for local communities and beyond, since estuarine fish are sold elsewhere to generate income and
supply distant markets. In the Cayapas-Mataje delta in Esmeraldas Province
(Ecuador/Colombia border), at least 6000 inhabitants directly rely on mangrove
resources for living (Ocampo-Thomason 2006). Artisanal fishing and arc-shells
picking (Anadara tuberculosa, A. similis and A. grandis) are the main economic
activities (Ocampo-Thomason 2006). However, changes such as African palm culture and commercial shrimp farming are having an impact on the mangrove ecosystem. Construction of shrimp farms has led to the destruction of arc-shells recruiting
and living grounds and damage to agricultural land (Ocampo-Thomason 2006).
Traditional communities responded to these changes by creating new management strategies agreed among political, ecological and social organizations. Two
movements came together in the north of Esmeraldas to defend the mangrove areas,
the Fundación para la Defensa Ecológica in 1989 and the Black Communities
Process. After 5 years of mobilizations and campaigns, the Ecuadorian government
granted the area status of ecological reserve, the Ecological Mangrove Reserve
Cayapas-Mataje (Ocampo-Thomason 2006). It led to the implementation of a novel
practice called ‘custodias’, a piece of land protected by recognized community
leader who retains traditional knowledge in resource management. It has been calculated that 98% of illegal mangrove removal has stopped, confirming the potential
success of this aproach (Ocampo-Thomason 2006).
Another issue for estuarine ecological processes is the lack of basic sanitation
(sewage treatment), often the worst concern in estuarine pollution and degradation
(Costa and Barletta 2016). High loads of solid wastes are also contaminating estuaries increasing the risk of higher plastic debris ingestion (macro or micro) by estuarine fauna (Lima et al. 2014; Ferreira et al. 2016) (Table 20.1). Wastewater from
household, industries and farms generate high amounts of pesticides (POPs) and
heavy metal that directly affect water and aquatic biomass quality (Costa et al. 2009;
Barletta et al. 2012; Silva-Cavalcanti et al. 2016). Shellfish species, for example,
depend on good water and suspended particulate organic matter quality to generate
meat safe for consumption. Efforts to better use of surrounding land and treatment
of effluents are important in determining shellfish survival, meat quality and livelihoods (Barletta and Costa 2009).
M. Barletta et al.