ArticlePDF Available

Tropical Mangrove Ecosystems

Authors:
Alistar Ian Robertson at University of Western Australia
Alistar Ian Robertson
Daniel M. Alongi at Tropical Coastal & Mangrove Consultants
Daniel M. Alongi
  • Tropical Coastal & Mangrove Consultants
Download full-text PDF
Read full-text
Download citation
Content uploaded by Alistar Ian Robertson
Author content
All content in this area was uploaded by Alistar Ian Robertson on Jul 11, 2014
Content may be subject to copyright.
Coastal and Estuarine Studies
Managing Editors'
Malcolm J. Bowman Richard T. Barber
Christopher N.K. Mooers John A. Raven
Coastal
and Estuarine Studies
41
A.I. Robertson and D.M. Alongi (Eds.)
Tropical Mangrove
Ecosystems
American Geoph
Washington, DC
ysical Union
Managing Editors
Malcolm J. Bowman
Marine Sciences Research Center, State University of New York
Stony Brook, N.Y. 11794, USA
Richard T. Barber
Duke Marine Laboratory
Beaufort, N.C. 28516, USA
Christopher N.K. Mooers
Ocean Process Analysis Laboratory
Institute for the Study of the Earth, Oceans and Space
University of New Hampshire
Durham, N.H. 03824-3525, USA
John A. Raven
Dept. of Biological Sciences, Dundee University
Dundee, DD1 4HN, Scotland
Editors
Alistar I. Robertson
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Daniel M. Alongi
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Library of Congress Cataloging-in-Publication Data
Tropical mangrove ecosystems / A.I. Robertson and D.M. Alongi (eds.).
p. cm.- (Coastal and estuarine series; 41)
Includes bibliographical references.
ISBN 0-87590-255-3
1. Mangrove swamp ecology. I. Robertson, A. I. (Alistar I.)
II. Alongi, D. M. (Daniel M.) III. Series.
QH541.5.M27T76 1992
574.5'26325•dc20
ISSN 0733-9569
ISBN 0-87590-255-3
92-44357
CIP
Copyright 1992 by the American Geophysical Union, 2000 Florida Avenue, NW, Washington,
DC 20009, U.S.A.
Figures, tables, and short excerpts may be reprinted in scientific books and journals if the source
is properly cited.
Authorization to photocopy items for internal or personal use, or the internal or personal use of
specific clients, is granted by the American Geophysical Union for libraries and other users
registered with the Copyright Clearance Center (CCC) Transactional Reporting Service,
provided that the base fee of $1.00 per copy plus $0.10 per page is paid directly to CCC, 21
Congress Street, Salem, MA 10970. 0733-9569/87/$01. +. 10.
This consent does not extend to other kinds of copying, such as copying for creating new
collective works or for resale. The reproduction of multiple copies and the use of full articles or the
use of extracts, including figures and tables, for commercial purposes requires permission from
AGU.
Printed in the United States of America.
Preface
Mangrove forests are a dominant feature of tropical coasts. Like their terrestrial counterparts
these forests are under threat worldwide through a variety of destructive human practices. As
is also the case with tropical terrestrial forests, management decisions about mangrove
ecosystems are currently being made often without adequate fundamental knowledge of the
processes controlling natural ecosystem function.
Since the mid 1970's, the Australian Institute of Marine Science (ALMS) has had in place
a research program investigating the structure and dynamics of mangrove ecosystems in
tropical Australia. Early results of this research were summarized in 1982 in the book
entitled Mangrove ecosystems in Australia.' structure, function and management, edited by
B.F. Clough. We felt that the time was ripe for a review of work during the decade 1981-
1991, and so approached all past and present AIMS mangrove research workers to contribute
to this volume. With the exception of Steve Blaber and Colin Woodroffe, all authors have
worked at AIMS as staff members, or visiting scientists. We thought it appropriate that since
John Bunt instigated much of the early work on mangrove ecosystems in northeastern
Australia, he should introduce this volume.
While we are sure that this volume will serve as a useful source book for managers of
mangrove wetlands, most chapters identify the often substantial gaps in our knowledge of
these systems. Given the rate of loss of mangrove forests worldwide, the challenge for future
workers on tropical mangrove systems will be to fill these important gaps in our knowledge,
while at the same time publicizing their research results and making them available to
managers (see Chapter 11, this volume).
All major chapters were reviewed by one external and one AIMS scientist. We thank
Marylin Ball, Betsy Jackes, Chad Pattiaratchi, Richard Pearson, Gordon Thayer, Bruce Thom,
Ivan Valiela and Bill Wiebe for review of chapters. All word processing was performed by
Frances Conn, Steve Clarke, Rhonda Lyons, Sue Smith and Kim Wicks. Marty Eden produced
all of the final figures and Christine Cansfield-Smith produced the camera ready text and did the
copy editing. We also acknowledge the scientific support sections at AIMS for their
professional assistance with much of the research reviewed in this volume.
Alistar Robertson and Daniel Alongi
Townsville, June 1992.
Contents
Preface
List of Contributors
ix
1 Introduction
J.S. Bunt
Mangrove sediments and geomorphology
C. Woodroffe
Mangrove hydrodynamics
E. Wolanski, Y. Mazda and P. Ridd
43
Mangrove floristics and biogeography
N.C. Duke
63
5 Forest structure
T.J. Smith III
101
Benthic communities
D.M. Alongi and A. Sasekumar
137
Plankton, epibenthos and fish communities
A.I. Robertson and S.J.M. B laber
173
Primary productivity and growth of mangrove forests
B.F. Clough
225
Nitrogen and phosphorus cycles
D.M. Alongi, K.G. Boto and A.I. Robertson
251
10 Food chains and carbon fluxes
A.I. Robertson, D.M. Alongi and K.G. Boto
293
11 Concluding remarks' research and mangrove conservation
A.I. Robertson
327
List of Contributors
Dr D.M. Alongi
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Dr B.F. Clough
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Dr S.J.M. B laber
CSIRO Marine Laboratories
PO Box 120
Cleveland
Queensland 4163
AUSTRALIA
Dr N.C. Duke
Smithsonian Tropical Research Institute
Box 2072
Balboa
REPUBLIC OF PANAMA
Dr K.G. Boto
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Prof. Y. Mazda
School of Marine Science and Technology
Tokai University
Orido
Shimizu
Shizuoka
JAPAN 424
Dr J.S. Bunt
4/6 McDonald Street
Potts Point
N.S.W. 2011
AUSTRALIA
Dr P. Ridd
Department of Physics
James Cook University of North Queensland
Townsville
Queensland 4811
AUSTRALIA
ix
x List of Contributors
Dr A.I. Robertson
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Dr E Wolanski
Australian Institute of Marine Science
PMB No 3
Townsville MC
Queensland 4810
AUSTRALIA
Dr A. Sasekumar
Department of Zoology
University of Malaya
Kuala Lumpur
MALAYSIA
Dr T.J. Smith III
Rookery Bay National Estuarine Research
Reserve
Florida Department of Natural Resources
10 Shell Island Road
Naples
Florida 33962
U.S.A.
Dr C. Woodroffe
Department of Geography
University of Wollongong
PO Box 1144
Wollongong
N.S.W. 2500
AUSTRALIA
... Similar to the Sinsin et al. [14], the best emergence rates were obtained with low and moderate salinity levels, confirming that the application of salt nutrients within this range can speed up propagules emergence in R. racemosa seedling production. Salinity influences seedling emergence through its effect on water and osmotic potential [32][33][34]. Previous studies have demonstrated that high salt concentration decreased emergence and growth rates in Rhizophora species are considered to be less tolerant to salt than Avicennia [30,33]. ...
Effect of Salinity and Substrate on the Emergence and Growth of Propagules of the Mangrove Species Rhizophora racemosa in the Sassandra-Dagbego Ramsar Complex, Côte d’Ivoire
Article
  • Jun 2024
This study aimed to evaluate the behaviour of seeded propagules of Rhirophora racemosa (R. racemosa) on different substrates and under different salinity levels. Three substrates including sand, mud and a mixture of the two were tested together with tree salinity levels (low 5%, moderate 10% and high 25%). R. racemosa seedlings were more likely to emerge and grow under moderate and low salinity conditions. The propagules had significant early growth in mud compared to sand and mud-sand mixture. The combined effect of salt and substrate influenced significantly propagules performance in nursery (p<0.001). High propagules emergence and growth were observed in the combination mud and salt treatments as compared to sand and san-mud mixture substrates. These results provide valuable information for the management and restoration of mangroves, highlighting the optimal environmental conditions for the successful regeneration of this species.
View
... Dichos ecosistemas ofrecen numerosos beneficios y servicios (Saenger, 2002b). Muchos de estos, fundamentales para la adaptación y la resiliencia ante el cambio climático en zonas costeras, lo que incluye la protección contra marejadas y el aumento del nivel del mar, la prevención de la erosión a lo largo de las costas, la regulación de la calidad del agua en zonas costeras, el reciclaje de nutrientes, la retención de sedimentos, la provisión de hábitat para diversas especies marinas en peligro y de importancia comercial, y la seguridad alimentaria para muchas comunidades costeras en todo el mundo (Robertson & Alongi, 1992;Hogarth, 1999;Beck et al., 2001;Kathiresan & Bingham, 2001;Saenger, 2002;Mumby, 2006;Barbier et al., 2011;Cullen-Unsworth & Unsworth, 2013). ...
Informe del estado de los ambientes y recursos marinos y costeros de Colombia 2022
Technical Report
Full-text available
  • Aug 2023
El informe está compuesto por 8 capítulos, donde el primero incluye la descripción de los espacios oceánicos y zonas costeras e insulares de Colombia, las unidades de gestión ambiental, establecidas por la Política Nacional Ambiental para el Desarrollo Sostenible de los Espacios Oceánicos y las Zonas Costeras e Insulares de Colombia. El capítulo II presenta avances en el conocimiento del medio abiótico, a partir de estudios de sistema de carbonatos, sólidos suspendidos, Clorofila-a (Chl-a), condiciones oceanográficas, dinámica litoral en tres sitos, caracterización general y geomorfológica de la plataforma continental al norte del departamento del Magdalena y del Pacífico colombiano, así como la calidad de las aguas marinas y costeras que incluye un análisis en playas turísticas, y también los indicadores de “salud” para arrecifes coralinos, pastos marinos y manglares. En el capítulo III, se describen las causas y tensores del cambio en los ecosistemas marinos y costeros, así como sus servicios de provisión de alimento y aprovechamiento por la pesca artesanal o industrial, incluyendo la operación estadística de presión pesquera artesanal. El capítulo IV contiene el tema de instrumentos de gestión, en el cual se describen los avances en el manejo integrado de la zona costera desde ejercicios de planificación espacial marina desarrollados a escala regional, el avance en el fortalecimiento de capacidades en manejo integrado de zonas costeras y el estado de la gestión de las áreas marinas protegidas. El capítulo V describe y analiza el estado del conocimiento y los vacíos de información que se tienen sobre los ecosistemas marinos y costeros de Colombia, para este año se incluyeron 3 nuevos capítulos que ilustran el primer mapa oficial de de manglares, la compariación entre los eventos climáticos extremos huracán Iota (2020) y Julia (2022), sobre las islas de Providencia y Santa Catalina. Y por último avances en las estimaciones de carbono azul en la zona costera colombiana. De este modo, el INVEMAR continúa generando y divulgando conocimiento para la formulación de políticas y la toma de decisiones que conduzcan al mejoramiento de la calidad de vida de los colombianos
View
... So far, mostly two-dimensional approaches were used to access forest structural complexity, e.g. through stem distribution pattern (Clark and Evans, 1954;Füldner, 1995), diameter distributions curves (Westphal et al., 2006), basal area (Smith, 1992), or combinations of all those patterns . However, such assessments have clear disadvantages, as they ignore the natural structural variability of the most complex part of a tree, the crown. ...
Simulation of silvicultural treatments based on real 3D forest data from mobile laser scanning point clouds
Article
Full-text available
  • Jan 2023
Forest management has a direct influence on the structure and stability of forests. In this study, we used the 3D data from mobile laser scanning in real forest stands dominated by European beech (Fagus sylvatica L.) to simulate different silvicultural treatments and assess their impact on the structural complexity and short-term economic return. For the structural assessment, we used the box-dimension (Db), a holistic measure of structural complexity in forest. The expected net revenues of the silvicultural treatments were used as a proxy for short-term economic gain. We simulated six different treatments in 19 different real-world forest stands. The results showed that each treatment had a negative impact on the structural complexity of the stands but with varying severity. The treatments with the smallest effect on stand structural complexity showed the highest net revenue, indicating no trade-offs if a forest owner strives for small stand structural changes and high economic return. The approach used here allows quantifying the structural and economic consequences of different treatments in forest stands prior to the actual application in the real world. This holds large potential for decision making according to the forest owner's objective.
View
... Nevertheless, among the environmental variables evaluated, the mean diurnal range of temperature and the mean sea surface salinity had the greatest effect on mangrove distribution. Air temperature and relative humidity can act to modulate stomatal conductance and evapotranspiration (Robertson and Alongi, 1992;Quisthoudt et al., 2012), directly impacting the physiological development of mangroves. In addition, salinity is one of the most significant constraining factors affecting mangrove forests (Hutchings & Saenger 1987;Ball, 1988): although A. marina has been observed to be a highly tolerant species to salinity (Burchett et al., 1989). ...
Mangrove distribution and afforestation potential in the Red Sea
Article
  • Jun 2022
Mangrove ecosystems represent one of the most effective natural environments for fixing and storing carbon (C). Mangroves also offer significant co-benefits, serving as nurseries for marine species, providing nutrients and food to support marine ecosystems, and stabilizing coastlines from erosion and extreme events. Given these considerations, mangrove afforestation and associated C sequestration has gained considerable attention as a nature-based solution to climate adaptation (e.g., protect against more frequent storm surges) and mitigation (e.g. offsetting other C-producing activities). To advance our understanding and description of these important ecosystems, we leverage Landsat-8 and Sentinel-2 satellite data to provide a current assessment of mangrove extent within the Red Sea region and also explore the effect of spatial resolution on mapping accuracy. We establish that Sentinel-2 provides a more precise spatial record of extent and subsequently use these data together with a maximum entropy (MaxEnt) modeling approach to: i) map the distribution of Red Sea mangrove systems, and ii) identify potential areas for future afforestation. From these current and potential mangrove distribution maps, we then estimate the carbon sequestration rate for the Red Sea (as well as for each bordering country) using a meta-analysis of sequestration values surveyed from the available literature. For the mangrove classification, we obtained mapping accuracies of 98 %, with a total Red Sea mangrove extent estimated at approximately 175 km2. Based on the MaxEnt approach, which used soil physical and environmental variables to identify the key factors limiting mangrove growth and distribution, an area of nearly 410 km2 was identified for potential mangrove afforestation expansion. The factors constraining the potential distribution of mangroves were related to soil physical properties, likely reflecting the low sediment load and limited nutrient input of the Red Sea. The current rate of carbon sequestration was calculated as 1034.09 ± 180.53 Mg C yr-1, and the potential sequestration rate as 2424.49 ± 423.26 Mg C yr-1. While our results confirm the maintenance of a positive trend in mangrove growth over the last few decades, they also provide the upper bounds on above ground carbon sequestration potential for the Red Sea mangroves.
View
... Il existe une forme de zonation dans la distribution spatiale des différentes espèces de palétuviers, qui occupent des étages distincts avec peu de chevauchement. Les espèces de palétuviers sont organisées en bande de végétation en fonction de la topologie du terrain, de la hauteur des marées, et de la durée d'immersion des palétuviers dans l'eau de mer (Robertson and Alongi, 1992). Des gradients environnementaux entrent aussi en jeu, tels que la salinité du substrat, la composition du sol et de l'eau de surface, la disponibilité en nutriments et la température (Ball, 1998). ...
Traits écophysiologiques et comportementaux de trois espèces de crabes soumis à différents niveaux de stress anthropique dans les mangroves insulaires du Canal du Mozambique
Thesis
Full-text available
  • Feb 2022
Parmi les phénomènes d'origine anthropique impactant les écosystèmes de mangrove, l'apport d'éléments nutritifs issus des eaux usées domestiques est souvent associé à une meilleure productivité végétale. D'autres compartiments du système sont pourtant parfois négativement impactés, notamment la macrofaune benthique dont les représentants sont souvent considérés comme des espèces ingénieurs de l’écosystème. Au cours de cette thèse, nous avons cherché à étudier les réponses écophysiologiques de trois espèces de crabes de mangroves présents dans le Canal du Mozambique, exposés aux apports d’eau usée domestique ou à de l’ammonium, étudié en tant que potentiel proxy d’enrichissement azoté. Différents marqueurs physiologiques et comportementaux ont été mis en place pour répondre à trois objectifs s’appuyant sur des niveaux intégratifs et des échelles spatiales différentes. Dans une première partie, nous avons cherché à compléter les connaissances sur les réponses physiologiques d’une espèce de crabe, Neosarmatium africanum, Sesarmidae occupant la partie haute de la mangrove, parfois directement exposée aux apports d’effluents domestiques sur l’un site d’étude (mangrove de Malamani, Mayotte) en nous focalisant sur un organe métabolique majeur, l’hépatopancréas. Dans une deuxième partie, nous avons cherché à mieux comprendre quelles potentielles réponses physiologiques et comportementales à l’échelle individuelle pouvaient être impliquées dans la modification des communautés de crabes observées dans des zones régulièrement impactées par l’apport d’eau usée domestique. Nous avons pour cela étudié une espèce de crabe violoniste, Paraleptuca chlorophthalmus, Ocypodidae, dont l’abondance diminue drastiquement sur les zones impactées de la mangrove de Malamani. Nos résultats montrent des réponses à court terme (explosion de la consommation d’oxygène, comportement de fuite et d’émersion) qui pourraient devenir délétères lors d’expositions ponctuelles mais chroniques, comme c’est souvent le cas dans le milieu naturel. Enfin, nous avons cherché à comprendre s’il existait une vulnérabilité différentielle face à des variations de salinités et des apports d’éléments nutritifs (ammonium) sur deux espèces de crabes violonistes génétiquement proches mais vivant dans des conditions environnementales opposées : mangrove de Malamani à Mayotte considéré comme écosystème anthropisé et la mangrove d’Europa (îles Eparses, Sud du Canal du Mozambique) considérée comme écosystème pristine. Les résultats indiquent que les crabes de Mayotte, régulièrement exposés à l’eau douce et aux effluents domestiques, semblent plus tolérants aux variations de salinité et développent des acclimatations physiologiques face à l’exposition à l’ammonium, ce que les crabes d’Europa ne développent pas. L’ensemble des résultats renforcent d’une part les connaissances sur la physiologie de ces ingénieurs de l’écosystème, mais permettent également de mieux lier les réponses individuelles obtenues en laboratoire, à celles observées à l’échelle des populations ou des communautés en milieu naturel. Ils encouragent la mise en place d’études concernant le suivi des écosystèmes de mangroves du Canal du Mozambique à travers l’étude d’espèces potentiellement bioindicatrices et permettent de proposer une approche écophysiologique dans le domaine du suivi et de la conservation des milieux naturels.
View
View
Informe del estado de los ambientes y recursos marinos y costeros de Colombia 2023
Technical Report
Full-text available
  • Apr 2024
El informe está compuesto por 5 capítulos, donde el primero incluye la descripción de los espacios oceánicos y zonas costeras e insulares de Colombia, las unidades de gestión ambiental, establecidas por la Política Nacional Ambiental para el Desarrollo Sostenible de los Espacios Oceánicos y las Zonas Costeras e Insulares de Colombia. El capítulo II presenta avances en el estado del ambiente y de los ecosistemas marinos y costeros mediante el conocimiento del medio abiótico, a partir de estudios de condiciones oceanográficas, climáticas y dinámica litoral en tres sitos, caracterización general y geomorfológica de la plataforma continental del Caribe, del Pacífico colombiano y territorios insulares, así como la calidad de las aguas marinas y costeras que incluye un análisis en playas turísticas, y también los indicadores de “salud” para arrecifes coralinos, pastos marinos y manglares. En el capítulo III, se describen las causas y tensores del cambio en los ecosistemas marinos y costeros, así como sus servicios de provisión de alimento y aprovechamiento del recurso pesquero, incluyendo la operación estadística de presión pesquera artesanal. El capítulo IV contiene el tema de instrumentos de gestión de los espacios oceánicos y zonas costeras e insulares de Colombina, en el cual se describen los avances en el manejo integrado de la zona costera desde ejercicios de planificación espacial marina desarrollados a escala regional, el avance en el fortalecimiento de capacidades en manejo integrado de zonas costeras y el estado de la gestión de las áreas marinas protegidas, hasta estrategias de capacitaciones en el manejo integrado de zonas costeras mediante diversos cursos, además se presenta el indicador de fortalecimiento de capacidades en manejo integrado. El capítulo V describe y analiza el estado del conocimiento y los vacíos de información que se tienen sobre los ecosistemas marinos y costeros de Colombia, en esta ocasión se presentan las microalgas potencialmente nocivas las cuales causan impactos negativos en los organismos marinos. Adicionalmente, se presenta la contaminación causada por basura marina costera plástica y el indicador de especies bioprospectadas, los servicios ecosistémicos con su respectiva clasificación. Por último, el capítulo V presenta el potencial de Carbono Azul en Colombia y su importante papel en la mitigación del cambio climático, además de una línea de tiempo de las investigaciones en Carbono Azul para manglares y pastos marinos; y los avances en las estimaciones de carbono azul en la zona costera colombiana. De esta manera, el INVEMAR sigue contribuyendo activamente a la generación y difusión de conocimiento con el objetivo de apoyar la formulación de políticas y la toma de decisiones que promuevan el bienestar y la calidad de vida de los ciudadanos colombianos.
View
Potentially Toxic Metals in the Tropical Mangrove Non-Salt Secreting Rhizophora apiculata: A Field-Based Biomonitoring Study and Phytoremediation Potentials
Article
Full-text available
  • Jan 2023
The present study evaluated the potentials of phytoremediation and the biomonitoring of potentially toxic metals (PTMs) (Zn, Ni, Fe, Pb, and Cu) in the mangrove leaves of Rhizophora apiculata from the tropical mangrove ecosystem in the Sepang Besar River and Lukut River, Peninsular Malaysia. Overall, the present studies concluded that (a) the levels of essential Fe, Cu, and Zn in lamina are significantly (p < 0.05) higher than in MP, (b) the levels of Pb and Ni in MP are significantly (p < 0.05) higher than in lamina, (c) the lamina has better potential as a phytoremediator of Cu, Zn, and Fe, while MP is a better potential phytoremediator of Pb and Ni, (d) lamina is a potential biomonitoring agent of potentially toxic metals based on better correlation coefficients with the surface sedimentary geochemical fractions, and (e) metal uptake in the mangrove leaves and comparative levels of metals is low with reported studies. Specifically, based on bioconcentration factors (BCF), their most obtained values were considered low (<1), suggesting that R. apiculata can be considered as a low-efficiency plant for the bioaccumulation of PTM. However, the present findings also suggested that R. apiculata may be classified as a potential phytoremediator for Zn, Cu, Pb, and Ni in the leaves, as indicated by higher metal accumulation in the MP, with BCFEFLE values > 1.0; BCFAR > 1.0 for Cu, Pb, and Ni. The mangrove leaves are potential biomonitors of PTMs since positive correlations of PTMs were found between the leaves and their habitat surface sediments. Having been identified as a potential phytoremediator and biomonitor of PTMs, the present study emphasized the possibility of establishing a framework for managing the coastal aquatic ecosystems along the mangrove ecosystems of Sepang and Lukut.
View
Participatory Conservation and Management of the Godavari Mangrove Wetlands, Andhra Pradesh, India
Chapter
Full-text available
  • Aug 2022
Godavari mangrove wetland in Andhra Pradesh is one of the important coastal wetlands providing livelihood security to the coastal community and ecological security to the coastal areas. Mangroves are potential carbon sinks contributing reduction in the impacts of climate change. Despite these benefits, mangroves are being degraded due to both manmade and natural causes. Participatory mangrove conservation and management approach gained greater significance in recent years in South Asian countries. M. S. Swaminathan Research Foundation (MSSRF) is implementing mangrove conservation and management programs from 1996 involving multiple stakeholders, namely the state forest department, revenue department, local self-government and the community. Gender-balanced village-level institutions (VLIs) were formed to plan, implement and monitor the mangrove conservation activities. Participatory rural appraisal was conducted to identify the status of mangrove resources, their utilization pattern and the issues related to its conservation and management. Causes for mangrove degradation were assessed jointly with the stakeholders. Majority of the degraded areas in the wetland were elevated, and tidal flushing was rare for most part of the year leading to hypersaline conditions of the soil. The degraded mangrove areas were restored through digging shallow canals to facilitate tidal water flow into the degraded area. Tidal flow in the canals reduces the soil salinity which enables the mangroves to grow. Nursery-raised mangrove saplings were planted along the canals. Local community played an active role in the mangrove restoration works which provided employment opportunity as well as a sense of ownership of the restored area. Apart from mangrove restoration, socioeconomic activities were carried out to improve the livelihoods of the community, and alternatives were provided for the mangrove-dependent community. The assessment of changes in the land use and land cover between 2000 and 2020 showed an increase in the mangrove area from 13,105 to 15,953 ha indicating the impact of mangrove conservation efforts. MSSRF restored an area of about 175 ha of degraded mangroves between 1996 and 2008, while the state forest department has restored nearly 2500 ha between 1990 and 2020 jointly with the stakeholders. This paper deals the approaches, strategies and impacts of participatory mangrove management in the Godavari wetland.
View
Feeding Ecology and Trophic Dynamics
Chapter
  • Mar 2022
This chapter examines the ways in which estuarine fishes interact both with their habitat, and with each other, in relation to food and feeding. The ways in which diet and feeding may change with size and age are also discussed. The diverse feeding specialisations and dietary flexibility employed by different groups of fishes are reviewed, with the various trophic levels occupied by fishes, from herbivorous to piscivorous, being documented. In addition, examples are given of food web structures in estuaries, how these may be influenced by different primary producers and type of estuary, as well as by perturbations. The use of stable isotopes in interpreting these trophic structures is examined and examples presented to illustrate how modern techniques have progressed our understanding of fish feeding ecology in estuaries. The role of piscivorous fish, invertebrate, reptile and mammalian predators on the ichthyofauna of estuaries is also assessed.
View
ResearchGate has not been able to resolve any references for this publication.