Cover
FAO FISHERIES TECHNICAL PAPER 314





Principles of hydraulic management of coastal lagoons for aquaculture and fisheries




CONTENTS

by
John M. Miller
Leonard J. Pietrafesa
North Carolina State University
at Raleigh, USA
Ned P. Smith
Harbor Branch Oceanographic Institution, Inc.
Fort Pierce, Florida, USA

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-40
ISBN 92-5-102992-X

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner.Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, 00100 Rome, Italy.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 1990
©FAO

PREPARATION OF THIS DOCUMENT

This is one of a series of Technical Papers on the Management of coastal lagoons for fisheries and aquaculture. The technical papers are a follow-up to the FAO Expert Consultation on the Management of Coastal Lagoon Fisheries (Rome, September 1983; papers published in FAO General Fisheries Council for the Mediterranean Studies and Reviews No. 61, Vols. 1 and 2, 1984). Other Technical Papers in the present series include those on bordigues (Chauvet, 1988), and Italian coastal lagoon fisheries and aquaculture (Ardizzone, Cataudella, Rossi, 1988).

Comments are welcome, and should be addressed to the Chief, Inland Water Resources and Aquaculture Service, FIRI, FAO, Via delle Terme di Caracalla, 001000 Rome, Italy.

The references have been included as presented by the authors and not edited in accordance with FAO style.

The cover illustration shows the hydraulic response (water level) of Pamlico Sound, NC, USA to a 10m s-1 NW wind. Drawing by Luann Salzillo.

Distribution:

FAO Fisheries Department
FAO Regional Fisheries Officers
Directors of Fisheries
Marine and Inland Selectors

Miller, J.M.; Pietrafesa, L.J.; Smith, N.P.
Principles of hydraulic management of coastal lagoons for aquaculture and fisheries.
FAO Fisheries Technical Paper. No. 314. Rome, FAO. 1990. 88p.
ABSTRACT
This document is prepared for fisheries biologists, managers and administrators concerned with lagoon fisheries and aquaculture. Our main objective is to draw attention to the need for greater understanding of relationships between the hydraulics and productivity of lagoon fish and shellfish. The fishery yields from lagoons vary widely, and, probably, predictably, once such relationships are understood. Furthermore, the productivities of many lagoons could probably be enhanced by hydraulic manipulations, but the hydraulic manipulation is presently risky, except in dystrophic lagoons.
The document includes a description of lagoon physics, how hydraulics are likely linked to lagoon productivity, how lagoons might be expected to respond to hydraulic alterations, and a protocol for physical investigations. This latter is a necessary step to protect as well as enhance fisheries and aquaculture resources in lagoons, which are especially vulnerable to degradation and overexploitation.

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.

CONTENTS

1.  INTRODUCTION-PERSPECTIVE

1.1  Background

1.2  Objectives

2.  PHYSICAL OCEANOGRAPHY OF LAGOONS

2.1  Introductory Remarks

2.1.1  Distinctive physical features

2.1.2  Objectives

2.2  Water Balance

2.2.1  Basic concepts

2.2.2  Advective processes

2.2.3  Tidal circulation

2.2.4  Nontidal circulation

2.2.5  Hydrodynamic exchange with the ocean

2.2.6  Pass dynamics

2.3  Salt Balance

2.3.1  Governing equations

2.3.2  Advective vs. diffusive transport

2.4  Heat Balance

2.4.1  Introductory remarks

2.4.2  The heat budget equation

2.4.3  Special considerations

2.5  Summary

3  RELATIONSHIPS BETWEEN PHYSICAL PROCESSES AND PRODUCTION IN LAGOONS

3.1  Introduction

3.2  Hydraulics, Scalars and Production

3.2.1  Oxygen

3.2.2  Temperature

3.2.3  Salinity

3.3  Hydraulics, Trophic Factors and Production

3.3.1  Vertical mixing and primary production

3.3.2  Hydraulics, nutrients and production

3.3.3  Hydraulic replacement time and biomass accumulation

3.3.4  Hydraulics and benthic production

3.4  Hydraulics, Predation and Production

3.5  Hydraulics, Colonization and Production

3.5.1  Hydraulics and migration through passes

3.5.2  Hydraulics and dispersal in lagoons

3.6  Summary

4  HYDRAULIC MANAGEMENT

4.1  Effects of Modified Freshwater Input

4.1.1  Abiotic environment

4.1.2  Colonization

4.1.3  Primary production

4.1.4  Secondary production

4.1.5  Examples of modified freshwater input

4.2  Effects of Modification of Exchange with the Ocean

4.2.1  Abiotic environment

4.2.2  Colonization

4.2.3  Primary production

4.2.4  Secondary production

4.2.5  Examples of modified exchange with the ocean

4.3  Effects of Modification of Internal Circulation

4.3.1  Abiotic environment

4.3.2  Colonization

4.3.3  Primary production

4.3.4  Secondary production

4.3.5  Examples of modified internal circulation

4.4  Summary

5  A PROTOCOL FOR HYDRAULIC ASSESSMENT AND MANAGEMENT OF LAGOONS

5.1  General Considerations

5.2  Atmospheric Weather and Climatological Data

5.3  Bathymetric Survey

5.4  Freshwater Inputs

5.5  In situ Studies

5.5.1  Diurnal, semi-diurnal and super semi-diurnal time scales

5.5.2  Subseasonal cycles

5.5.3  The annual cycle

6  REFERENCES