front (southwestern Spain) may be attributed to the
genesis of littoral cordons. This process may also have
been active in the past at the delta front that forms the outlet of the Rhine, Meuse, and Elm rivers in the Netherlands.
Relict littoral cordons may remain submerged under rising sea-level conditions, and they may shape sedimentary
ridges in front of many coastal areas. These features are
obviously very different from reefs or actual tectonic ridges.
Bibliography
Bores, P. S., 1978. Shore classification-simple forms with prevailing
wind wave action. In III IAEG International Congress Proceedings, Madrid, Spain, pp. 150–169.
Finkl, C. L., 2004. Coastal classification: systematic approaches to
consider in the development of a comprehensive scheme. Journal of Coastal Research, 20(1), 166–213.
King, C. A. M., 1972. Beaches and Coasts. London: Edward
Arnold.
Williams, S. J., 1982. Barrier island shorelines: an assessment of
their Genesis and evolution. In Florida Shore and Beach Association, Proceedings, 26th Annual Meeting, Tallahassee, FL,
pp. 188–199.
Cross-references
Bar
Barrier Island
Coastal Bays
Spit
LITTORAL ZONE
Michael J. Kennish
Department of Marine and Coastal Sciences,
School of Environmental and Biological Sciences,
Rutgers University, New Brunswick, NJ, USA
Synonyms
Intertidal zone
Definition
In an estuary, the littoral (intertidal) zone is defined
as the area between the high and low tide marks
(Kennish, 2001). In an ocean, many scientists define the
littoral zone more broadly as the area extending from
the shore to the edge of the continental shelf and
encompassing the supralittoral, eulittoral, and sublittoral
zones. As such, most of the littoral zone lies in the shallow
water region at sea where light penetrates to the bottom.
Characteristics
The intertidal zone of estuarine and marine environments
is highly variable in physical and chemical conditions.
Organisms inhabiting this zone must be able to withstand
multiple stresses associated with periodic exposure, strong
wave action and turbulence, shifting sediments, and susceptibility to predation from both terrestrial and aquatic
organisms (Kennish, 2001; Day et al., 2012; Levinton,
2013). Many organisms found along high-energy, rocky
intertidal zones are sedentary and firmly attached to
a substrate.
Bibliography
Day, J. W., Crump, B. C., Kemp, W. M., and Yanez-Arancibia,
A. (eds.), 2012. Estuarine Ecology, 2nd edn. New York:
Wiley-Blackwell.
Kennish, M. J. (ed.), 2001. Practical Handbook of Marine Science,
3rd edn. Boca Raton, FL: CRC Press.
Levinton, J. S., 2013. Marine Biology: Function, Biodiversity,
Ecology, 4th edn. Oxford: Oxford University Press.
Cross-references
Shoreline
Sublittoral Zone
LOBSTER MIGRATION
Jason S. Goldstein
Department of Biological Sciences, University of New
Hampshire, Durham, NH, USA
Definition
Lobsters frequent estuaries and bays throughout their
range and exhibit seasonal movements or migrations.
Background
Estuarine habitats are demanding marine environments
for crustaceans such as lobsters because these areas are
frequently subject to dramatic fluctuations in salinity and
temperature (Watson et al., 1999). Lobsters that reside in
estuarine systems therefore optimize their survival in this
complex habitat through both physiological (changes in
osmoregulation) and behavioral adaptations (behavioral
thermoregulation) (Crossin et al., 1998; Charmantier
et al., 2001). While adult clawed lobsters (Homarus
americanus) prefer higher salinities (20–25 psu) over
lower ones (10–15 psu) (Jury et al., 1994), females appear
much more sensitive to reduced salinity. Thus, there are
often differential movements by males and females in
estuaries in response to salinity or temperature gradients,
often setting up skewed sex ratios (Howell et al., 1999;
Jury and Watson, 2013).
Lobster migrations are generally considered direct
locomotory movements over a discrete time period and
toward environmental conditions that are different (see
Herrnkind, 1980). For example, Caribbean spiny lobsters
(Panulirus argus) typically exhibit fall movements from
bays and shallow coastal areas into deeper waters
(Herrnkind, 1980). A detailed examination of the seasonal
movements of clawed lobsters (H. americanus) into a New
England estuary (Great Bay, NH) showed that lobsters
moved into the estuary in the spring when salinities
LOBSTER MIGRATION
385
genesis of littoral cordons. This process may also have
been active in the past at the delta front that forms the outlet of the Rhine, Meuse, and Elm rivers in the Netherlands.
Relict littoral cordons may remain submerged under rising sea-level conditions, and they may shape sedimentary
ridges in front of many coastal areas. These features are
obviously very different from reefs or actual tectonic ridges.
Bibliography
Bores, P. S., 1978. Shore classification-simple forms with prevailing
wind wave action. In III IAEG International Congress Proceedings, Madrid, Spain, pp. 150–169.
Finkl, C. L., 2004. Coastal classification: systematic approaches to
consider in the development of a comprehensive scheme. Journal of Coastal Research, 20(1), 166–213.
King, C. A. M., 1972. Beaches and Coasts. London: Edward
Arnold.
Williams, S. J., 1982. Barrier island shorelines: an assessment of
their Genesis and evolution. In Florida Shore and Beach Association, Proceedings, 26th Annual Meeting, Tallahassee, FL,
pp. 188–199.
Cross-references
Bar
Barrier Island
Coastal Bays
Spit
LITTORAL ZONE
Michael J. Kennish
Department of Marine and Coastal Sciences,
School of Environmental and Biological Sciences,
Rutgers University, New Brunswick, NJ, USA
Synonyms
Intertidal zone
Definition
In an estuary, the littoral (intertidal) zone is defined
as the area between the high and low tide marks
(Kennish, 2001). In an ocean, many scientists define the
littoral zone more broadly as the area extending from
the shore to the edge of the continental shelf and
encompassing the supralittoral, eulittoral, and sublittoral
zones. As such, most of the littoral zone lies in the shallow
water region at sea where light penetrates to the bottom.
Characteristics
The intertidal zone of estuarine and marine environments
is highly variable in physical and chemical conditions.
Organisms inhabiting this zone must be able to withstand
multiple stresses associated with periodic exposure, strong
wave action and turbulence, shifting sediments, and susceptibility to predation from both terrestrial and aquatic
organisms (Kennish, 2001; Day et al., 2012; Levinton,
2013). Many organisms found along high-energy, rocky
intertidal zones are sedentary and firmly attached to
a substrate.
Bibliography
Day, J. W., Crump, B. C., Kemp, W. M., and Yanez-Arancibia,
A. (eds.), 2012. Estuarine Ecology, 2nd edn. New York:
Wiley-Blackwell.
Kennish, M. J. (ed.), 2001. Practical Handbook of Marine Science,
3rd edn. Boca Raton, FL: CRC Press.
Levinton, J. S., 2013. Marine Biology: Function, Biodiversity,
Ecology, 4th edn. Oxford: Oxford University Press.
Cross-references
Shoreline
Sublittoral Zone
LOBSTER MIGRATION
Jason S. Goldstein
Department of Biological Sciences, University of New
Hampshire, Durham, NH, USA
Definition
Lobsters frequent estuaries and bays throughout their
range and exhibit seasonal movements or migrations.
Background
Estuarine habitats are demanding marine environments
for crustaceans such as lobsters because these areas are
frequently subject to dramatic fluctuations in salinity and
temperature (Watson et al., 1999). Lobsters that reside in
estuarine systems therefore optimize their survival in this
complex habitat through both physiological (changes in
osmoregulation) and behavioral adaptations (behavioral
thermoregulation) (Crossin et al., 1998; Charmantier
et al., 2001). While adult clawed lobsters (Homarus
americanus) prefer higher salinities (20–25 psu) over
lower ones (10–15 psu) (Jury et al., 1994), females appear
much more sensitive to reduced salinity. Thus, there are
often differential movements by males and females in
estuaries in response to salinity or temperature gradients,
often setting up skewed sex ratios (Howell et al., 1999;
Jury and Watson, 2013).
Lobster migrations are generally considered direct
locomotory movements over a discrete time period and
toward environmental conditions that are different (see
Herrnkind, 1980). For example, Caribbean spiny lobsters
(Panulirus argus) typically exhibit fall movements from
bays and shallow coastal areas into deeper waters
(Herrnkind, 1980). A detailed examination of the seasonal
movements of clawed lobsters (H. americanus) into a New
England estuary (Great Bay, NH) showed that lobsters
moved into the estuary in the spring when salinities
LOBSTER MIGRATION
385