479
© Springer International Publishing AG 2017
C.W. Finkl, C. Makowski (eds.), Coastal Wetlands: Alteration and Remediation,
Coastal Research Library 21, DOI 10.1007/978-3-319-56179-0_16
Chapter 16
Estuarine Ecoclines and the Associated Fauna:
Ecological Information as the Basis
for Ecosystem Conservation
Mário Barletta, André R.A. Lima, Monica F. Costa, and David V. Dantas
Abstract Ecocline is defined as a “gradation from one ecosystem to another when
there is no sharp boundary between the two” containing relatively heterogeneous
communities influenced by gradual changes between river-dominated to marinelike waters. It creates heterogeneous habitats, differing in abiotic characteristics,
mainly water salinity. Estuarine fish fauna is highly influenced by the major annual
water quality shifts resulted from seaward river flow during the rainy season and
upstream coastal water inflow during drier seasons. Thus, faunal communities
change seasonally in terms of quali-quantitative variables or living strategies.
Estuarine ecocline can also set the seasonal retention, bioavailability or sinking of
dissolved oxygen, pollutants and microbiological contaminants whose effects are
crucial to determine the pattern of use, fish entering, tissue contamination and survival of early stages. Abrupt changes in climatic patterns or in the river flow induce
changes in the ecocline and fishes will respond by modifying assemblage structures.
The use of robust and consistent scientific information regarding fish fauna and their
ecocline can provide reliable ecological information. This generates descriptors of
reference conditions taking into account how human impacts affect coastal systems,
providing steps to guarantee the sustainable use of estuarine resources.
Keywords Environmental gradients • Marine pollution • Coastal management •
Anthropogenic impacts • Planned sampling design • Estuarine resources
conservation
M. Barletta (*) • A.R.A. Lima • M.F. Costa
Laboratório de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos
(LEGECE), Departamento de Oceanografia, Universidade Federal de Pernambuco (UFPE),
CEP 50740-550 Recife, Brazil
e-mail: barletta@ufpe.br
D.V. Dantas
Grupo de Tecnologia e Ciência Pesqueira (TECPESCA), Departamento de Engenharia de
Pesca, Centro de Ensino Superior da Região Sul (CERES), Universidade do Estado de Santa
Catarina (UDESC), CEP 88790-000 Laguna, Brazil
© Springer International Publishing AG 2017
C.W. Finkl, C. Makowski (eds.), Coastal Wetlands: Alteration and Remediation,
Coastal Research Library 21, DOI 10.1007/978-3-319-56179-0_16
Chapter 16
Estuarine Ecoclines and the Associated Fauna:
Ecological Information as the Basis
for Ecosystem Conservation
Mário Barletta, André R.A. Lima, Monica F. Costa, and David V. Dantas
Abstract Ecocline is defined as a “gradation from one ecosystem to another when
there is no sharp boundary between the two” containing relatively heterogeneous
communities influenced by gradual changes between river-dominated to marinelike waters. It creates heterogeneous habitats, differing in abiotic characteristics,
mainly water salinity. Estuarine fish fauna is highly influenced by the major annual
water quality shifts resulted from seaward river flow during the rainy season and
upstream coastal water inflow during drier seasons. Thus, faunal communities
change seasonally in terms of quali-quantitative variables or living strategies.
Estuarine ecocline can also set the seasonal retention, bioavailability or sinking of
dissolved oxygen, pollutants and microbiological contaminants whose effects are
crucial to determine the pattern of use, fish entering, tissue contamination and survival of early stages. Abrupt changes in climatic patterns or in the river flow induce
changes in the ecocline and fishes will respond by modifying assemblage structures.
The use of robust and consistent scientific information regarding fish fauna and their
ecocline can provide reliable ecological information. This generates descriptors of
reference conditions taking into account how human impacts affect coastal systems,
providing steps to guarantee the sustainable use of estuarine resources.
Keywords Environmental gradients • Marine pollution • Coastal management •
Anthropogenic impacts • Planned sampling design • Estuarine resources
conservation
M. Barletta (*) • A.R.A. Lima • M.F. Costa
Laboratório de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos
(LEGECE), Departamento de Oceanografia, Universidade Federal de Pernambuco (UFPE),
CEP 50740-550 Recife, Brazil
e-mail: barletta@ufpe.br
D.V. Dantas
Grupo de Tecnologia e Ciência Pesqueira (TECPESCA), Departamento de Engenharia de
Pesca, Centro de Ensino Superior da Região Sul (CERES), Universidade do Estado de Santa
Catarina (UDESC), CEP 88790-000 Laguna, Brazil