Table Of ContentThe Salton Sea
Developments in Hydrobiology 161
Series editor
H. J. Dumont
The Salton Sea
Proceedings of the Salton Sea Symposium,
held in Desert Hot Springs, California, 13-14 January 2000
Edited by
Douglas A. Barnum 1, John F. Elder2, Doyle Stephens3 & Milton Friend2
1 u.s. Geological Survey, Sacramento, CA, U.S.A.
2u.S. Geological Survey, Madison, WI, U.S.A.
3 Formerly of U.S. Geological Survey, Salt Lake City, UT, U.S.A.
Reprinted from Hydrobiologia, volume 473 (2002)
SPRINGER-SCIENCE+BUSINESS MEDIA, BV.
Library of Congress Cataloging-in-Publication Data
A C.I.P. Catalogue record for this book is available fram the Library of Congress.
ISBN 978-90-481-5989-5 ISBN 978-94-017-3459-2 (eBook)
DOI 10.1007/978-94-017-3459-2
Printed an acid-free paper
AII Rights reserved
© 2002 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 2002
Softcover reprint ofthe hardcover 1st edition 2002
No part of the material protected by this copyright notice may be repraduced
or utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without writlen permission from the copyright owner.
v
TABLE OF CONTENTS
Preface
M. Friend vii-xii
Chemical and physical characteristics of the Salton Sea, California
G. Chris Holdren, Andrew Montano 1-21
Chemical evolution of the Salton Sea, California: nutrient and selenium dynamics
Roy A. Schroeder, William H. Orem, Yousif K. Kharaka 23-45
Characteristics and contaminants of the Salton Sea sediments
Richard A. Vogl, Ryan N. Henry 47-54
Reconstruction of prehistoric Lake Cahuilla in the Salton Sea Basin using GIS and GPS
Joseph E. Buckles, Kazuyuki Kashiwase, Timothy Krantz 55-57
Simulation of wind-driven circulation in the Salton Sea: implications for indigenous
ecosystems
Christopher B. Cook, Gerald T. Orlob, David W. Huston 59-75
Preliminary studies of cyanobacteria, picoplankton, and virioplankton in the Salton
Sea with special attention to phylogenetic diversity among eight strains of filamentous
cyanobacteria
A. Michelle Wood, Scott R. Miller, W.K.w. Li, Richard W. Castenholz 77-92
Flagellate Cryptobia branchialis (Bodonida: Kinetoplastida), ectoparasite of tilapia from
the Salton Sea
Boris I. Kuperman, Victoria E. Matey, Steven B. Barlow 93-102
Metazooplankton dynamiCS in the Salton Sea, California, 1997-1999
Mary A. Tiffany, Brandon K. Swan, James M. Watts, Stuart H. Hurlbert 103-120
Freeliving nematodes from the Salton Sea
R. M. Warwick, D.M. Dexter, B. Kuperman 121-128
Cryptomonads from the Salton Sea, California
S.B. Barlow, P. Kugrens 129-137
The benthic invertebrates of the Salton Sea: distribution and seasonal dynamics
P.M. Detwiler, Marie F. Coe, Deborah M. Dexter 139-160
vi
Naked amoebae (Protozoa) of the Salton Sea, California
Andrew Rogerson, Gwen Hauer 161-177
The diatom flora of the Salton Sea, California
Carina B. Lange, Mary Ann Tiffany 179-201
Invertebrates of the Salton Sea: a scanning electron microscopy portfolio
Boris I. Kuperman, Victoria E. Matey, Deborah M. Dexter, Mary Ann Tiffany 203-216
Skeletal development in Hermesinum adriaticum Zacharias, a flagellate from the Salton
Sea, California
M.A. Tiffany 217 -221
Summer movements of desert pupfish among habitats at the Salton Sea
Ronald J. Sutton 223-228
Fish biology and fisheries ecology of the Salton Sea, California
Ralf Riedel, Lucille Caskey, Barry A. Costa-Pierce 229-244
Biology and migration of Eared Grebes at the Salton Sea
Joseph R. Jehl, Jr., Robert L. McKernan 245-253
The Salton Sea as critical habitat to migratory and resident waterbirds
W. David Shuford, Nils Warnock, Kathy C. Molina, Kenneth K. Sturm 255-274
Possible importance of algal toxins in the Salton Sea, California
Kristen M. Reifel, Michael P. McCoy, Tonie E. Rocke, Mary Ann Tiffany, Stuart H. Hurlbert,
D. John Faulkner 275-292
Avian disease at the Salton Sea
Milton Friend 293-306
Hydrobiolog;a 473: vii-xii, 2002.
D.A. Barnum, J.F Elder, D. Stephens & M. Friend (eds), The Salton Sea. vii
Preface
This issue of Hydrobiologia brings together a series of papers resulting from an intensified effort to describe the
current status of the physical and biological conditions present at California's Salton Sea. Most of the studies
Wl're contract investigations that were part of a project initiated in January 1998 to pursue the improvement of
environmental conditions at the Salton Sea. The remainder are independent investigations resulting in information
of importance for the Salton Sea Restoration Project. The information provided by those investigations is the most
holistic assembly of scientific knowledge about the Salton Sea ever brought together in a single publication. The
resulting findings provide an important foundation of knowledge for what has been stated to be, " ... one of the
w()rlds' most dynamic salt lakes ..." (Hart et a!., 1998). We hope this publication will serve as a catalyst to
sti mulate additional scientific investigations that will further enhance understanding of the dynamics of this unique
ec osystem. The purpose for these introductory comments is to place the scientific investigations reported on and
th,.: Salton Sea Restoration Project in context as entities, and to one another.
The Salton Sea
The Salton Sea was formed by floodwaters of the Colorado River during the period of 1905-1907 (Kennan, 1917).
This waterbody is the largest lake in California. It is approximately 58 km long, 14 to 22 km wide and has a surface
ar~a of 980 km2 (Hart et a!. 1998). The Salton Sea is located in the center of the Colorado Desert (Arnal, 1961)
in southern California and lies approximately 227 feet below sea level within the Salton Trough. At the time of
fNmation the Salton Sea was a freshwater lake but by 1929 had become almost as saline as ocean water because of
e\aporation and the solution of salts present on the basin floor prior to lake formation (Arnal, 1961). The current
salinity of the Salton Sea is approximately 44 g 1-1 (Hart et a!., 1998) and continuing to rise.
The formation of the Salton Sea created a large oasis within the desert that soon became a focal point for
land development associated with recreational opportunities afforded by this waterbody. Land developers also
touted the Salton Sea as a retirement haven (Kennan, 1917; du Buys & Myers, 1999). The "boom" for shoreline
development and public use of the Salton Sea that began during the 1930's started to wane during the mid-1960's
and collapsed during the 1970·s. To a large extent that shift in fortunes was due to rising water levels that flooded
sboreline properties, increasing salinity and other factors. The State Water Quality Control Board contracted with
a Ilrivate firm in 1964 to prepare preliminary plans for controlling water quality, primarily salinity, and secondarily
tc consider algal blooms. Stabilization of water levels was also to be considered (USDI & RCA, 1969). That action
\\JS followed by a series of evaluations and reports without any actions being taken (USDI & RCA, 1969; 1974;
Ormat, 1989; Ogden, 1996; Bureau of Reclamation et a!., 1997; USDI, 1998).
The Salton Sea Restoration Project
A n increasing occurrence of avian disease at the Salton Sea prompted an unsuccessful attempt by the Director of
the National Wildlife Health Center to stimulate the development of an ecosystem health project to address those
plOblems (U.S. Geological Survey, 1996). However, the unprecedented 1996 type C avian botulism mortality event
involving American white pelicans (Pelecanus erythrorhynchos) and California brown pelicans (P. occidentalis)
(National Wildlife Health Center Epizootic Database) served to focus prolonged national media attention on the
Salton Sea. In August 1997 the U.S. Fish and Wildlife Service and Bureau of Reclamation sponsored a work
shop in Palm Springs, California to develop a process to address the natural and cultural resource issues, and
[('search and investigation needs for any proposed engineering solutions to repair the Salton Sea (U.S. Fish and
Wildlife, 1997). In December 1997, the Secretary of the U.S. Department of the Interior announced a collaborative
a,!,reement between Interior and other stakeholders for a Salton Sea Restoration Project focused on improving the
viii
environmental quality of the Sea (USDI, 1997). The U.S. Bureau of Reclamation was designated as the project
federal co-lead and the Salton Sea Authority was designated as the co-lead for the State of California.
Project initiation in January 1998 had two major conditions. An independent Science Subcommittee was estab
lished to provide objective, enhanced scientific information about the Salton Sea ecosystem to serve as a foundation
for management decisions by the co-lead agencies relative to restoration actions to be pursued. Tn addition, the
co-lead agencies were required to comply with National Environmental Policy Act (NEPA) and California Envir
onmental Quality Act (CEQA) processes in developing their recommendations. They were also required to provide
their findings to the Secretary of the Interior by December 1999 for his transmittal to the Congress by January 2000.
The Science Subcommittee pursued its task through contracting for a series of reconnaissance studies to describe
the current state of the Salton Sea. Because of imposed time constraints the maximum amount of time that could be
allocated for individual studies was twelve months. The collective highlights from those studies were presented at
a January 2000 symposium held at Desert Hot Springs, California. Symposium presentations also included reports
from independent studies with information relevant for the restoration project.
Rather than being an end-point, the reconnaissance investigations are just the beginning of scientific needs
associated with the Salton Sea Restoration Project. Additional scientific investigations have been initiated to begin
addressing some of the specific problems that must be overcome for goal achievement. Those goals are to:
• maintain the Sea as a repository of agricultural drainage;
• provide a safe, productive environment at the Sea for resident and migratory birds and endangered species;
• restore recreational uses at the Sea;
• maintain a viable sport fishery at the Sea; and
• enhance the Sea to provide economic development opportunities.
A Strategic Science Plan was developed to guide an integrated, continuing science effort (Fig. I). That Plan calls for
the development of a Science Office to serve restoration project needs (Salton Sea Science Subcommittee, 2000). In
keeping with that Plan, in February 2000 the Science Subcommittee was replaced with an interim Science Office.
It is anticipated that a permanent Science Office will be authorized as part of Congressional approval and funding
for a large-scale restoration project.
Overview
Presenters at the January 2000 symposium were not required to provide manuscripts for publication. As a result,
several of those presentations are not included in this issue of Hydrobiologia. Nevertheless, the papers that are
provided address a broad spectrum of subject areas and clearly illustrate the dynamic nature of the Salton Sea and
the richness of biodiversity present. Symposium papers included within this overview are cited without dates.
Prehistoric and Native American peoples were closely associated with the large waterbodies that occupied the
Salton Trough and left behind cultural resources that are part of the richness of the area considerations. Buckles et
al. (this volume) delineated the prehistoric shorelines of those lakes as a foundation for archaeological and cultural
resources. Those factors are important in evaluating restoration alternatives for the Salton Sea and are themselves
areas for scientific investigations (Darnell, 1959; Schaefer et aI., 2000; Wilke & McDonald, 1989).
Cook et al. (this volume) investigated the circulation of the Salton Sea and developed a mathematical model for
describing water movement. They noted that circulation is driven primarily by wind stresses imposed on the water
surface and that those patterns affect the ecology of the Sea. Therefore, proposed actions that change the bathymetry
and configuration of the Sea can be expected to impact the environmental quality and existing ecological relations
of the Salton Sea. Continued enhancement of the circulation model for predictive impact purposes remains an
important area for scientific investigation.
The current chemical and physical conditions of the Salton Sea were evaluated by Holdren & Montano (this
volume). This investigation included water quality parameters, nutrients, trophic state variables, major cations and
anions, trace metals, organic compounds and provides comparisons with the classic publications of Arnal (1961)
and Walker (1961). Failure of Holdren & Montano to detect high levels of pesticides and other anthropogenic
chemical contaminants (other than nutrients) within the water column was counter to expectations. The distribution
ix
Figure 1.
of sediment types and sediment contaminants throughout the Salton Sea were also investigated. Vogl et al. (this
volume) found an absence of elevated concentrations of organic chemicals such as dichlorodiphenyltrichloethane
(D1 H) despite several decades of heavy DDT use in the surrounding agricultural areas. Those findings also differed
from expectations. Several heavy metals and selenium were found at elevated levels within some sediments but not
at other locations. The pattern of metal and selenium deposition also differed from expectations with the most
elevated levels seen in deep water areas rather than within the shallow delta area receiving input waters.
Other contaminant investigations have also resulted in unexpected findings. For example, Fialkowski & New
man (1998) concluded from their studies of barnacles (Balanus amphitrite) that the Salton Sea has not been
significantly polluted with heavy metals or that those metals are bring transferred from the water column to the
sediments. The lack of clear findings relative to contaminants are an indication of the need for greater understanding
of the fate, transport and biological effects of chemicals within the Salton Sea ecosystem.
The most comprehensive evaluations included in this publication are those for the limnology of the Salton Sea.
Those findings document far greater numbers of nonvertebrate species than the earlier studies of Arnal (1958,
1961) and the publication by Walker (1961). Many of the approximately 400 species found have not previously
been described within the scientific literature.
Investigations on the dynamics of metazooplankton populations extended existing studies to provide a three
year evaluation (Tiffany et al., this volume). Those studies disclosed two major changes in metazooplankton
dynamics since 1954-56 investigations by Carpelan (1961). Eight genera of cryptomonads from the Salton Sea
x
were recorded for the first time and one putative genus that may represent a new taxon remains under investigation
(Barlow & Kugrens, this volume). The authors note that the genera and species identified are typical of marine
rather than freshwater environments and may play an important role in primary productivity and as preferred food
organisms for zooplankton. The first investigations of the naked amoeboid protozoa of the Salton Sea disclosed 45
different morpho species (considered to be species), approximately 40% of which are new to science (Rogerson &
Hauer, this volume). The authors postulate that amoebae may be important in the cycling of carbon and nutrients
in the Salton Sea.
A high diversity of diatoms was also found. Ninety-four taxa were distinguished. Those taxa constituted
four general categories of diatom assemblages associated with plankton, benthos and algal mats, an epiphytic
community and freshwater assemblages at inflow points to the Sea (Lange & Tiffany, this volume). Even greater
numbers of Cilophora were found. One hundred and forty-one species within nine classes of citiates were collected
from eleven different shoreline sites around the perimeter of the Salton Sea. A follow-up collection resulted in an
additional thirty-five species. Those investigations by Small and others are documented within the Salton Sea
database (Salton Sea Science Office) but are not included within these proceedings.
The macro invertebrates of the Salton Sea include only a few species and the investigations of Detwiler et al.
(this volume) add several new species for this waterbody. The pileworm (Neanthes succinea) may be a key food
item for the fish of the Sea and also for a number of bird species. Area-weighted estimates of standing stock of this
invertebrate were two orders of magnitude less than biomass estimates made during 1956 investigations (Carpelan
& Linsley, 1961). Thirteen species of freeliving nematodes have been found, doubling the number of multicelluar
invertebrates known to occur at the Salton Sea (Warwick et aI., this volume). Scanning electron microphotographs
of 16 Salton Sea invertebrates including foraminiferans, a flatworm, a rotifer, annelids, crustaceans and insects
are provided along with comments on the morphology and function of structures visible in the images (Kuperman
et aI., this volume). Scanning electron microscopy was also used to study the skeletal development of Hermes
inum adricaticum, a rarely reported unicellular biflagellated organism with a solid siliceous skeleton (Tiffany, this
volume).
Cyanobacterial diversity in the Salton Sea is also great. Eighty-four pure strains, including filamentous and
unicellular forms were isolated from the water column and benthos. Those isolates fall within 11 described genera
except for two strains that do not conform to any currently recognized genus (Wood et aI., this volume). The authors
note that among those taxa are five known toxin producing species and they suggest that cyanobateria should be
considered as possible causes for some of the bird and fish mortality occurring at the Salton Sea. Initial studies of
algal toxicity showed a low level of activity in the brine shrimp lethality assay but an absence of activity in the
mouse bioassay (Reifel et aI., this volume). Additional investigations are being pursued under funding provided by
the Salton Sea Restoration Project.
Three of the four primary fishes of the Salton Sea are species from the Gulf of California. Orangemouth corvina,
Cynoscion xanthulus, sargo, Anisotremus davidsoni, and bairdiella, Bairdiella icistius, are the result of 1950
and 1951 introductions by the California Department of Fish and Game (Walker, 1961). Tilapia, Oreochromis
mossambicus, an exotic species for North America was introduced more recently by unknown means and has
become a dominant species.
Massive fish kills involving hundreds of thousands to millions of fish occur at the Salton Sea and are a subject
for concern and debate relative to causes. Studies on the ecology and biology of the fishes of the Salton Sea are
reported by Riedel et al. (this volume). They note fish population abundance, that dissolved oxygen influences
movement patterns for reproduction and feeding, and that the fish species present grow faster and have shorter
life spans than co-specifics elsewhere and for Salton Sea species of five decades ago. Young tilapia were found by
Kuperman et al. (this volume) to be infested by the flagellate parasite Cryptobia branchialis. The authors postulate
that mortality of young tilapia may arise from decreased gill function in response to Cryptobia infestation. The
study by Sutton (this volume) provides information on summer movement behavior of desert pupfish (Cyprinodon
macularius), an endangered species and the only native fish present in the Salton Sea.
The abundance of fish at the Salton Sea, the foodbase provided in adjacent agricultural fields, the geographic
location of the Salton Sea within the Pacific Flyway and drainage of more than 90 percent of historic interior
wetland acreage in California (Dahl, 1990) has resulted in the Salton Sea becoming California's crown jewel of
avian biodiversity and one of the crown jewels of North American avian biodiversity. The Salton Sea is of regional
