The Ecology of the Seagrasses of South Florida - USGS National ...

CHAPTER 1
INTRODUCTION
1.1 SEAGRASS ECOSYSTEMS Studies in the south Florida region
over the past 20 years have demonstrated
Seagrasses are unique for the marine the importance of the complex coastal
environment as they are the only land estuarine and lagoon habitats to the proplant
that has totally returned to the
sea. Salt marsh vegetation and mangroves
ductivity of the abundant fisheries and
wildlife of the region. Earlier studies
are partially submerged in sa1 t water, but describing the 1 ink between estuarine systhe
seagrasses llve fully submerged, tems and life cycles of important species
carrying out their entire life cycle com- focused on the mangrove regions of the
pletely and obl igately in sea water (Fig- Everglades (W,E, Odum et al, 1982), alure
l).
though the seagrass beds of Florida Bay
and the Florida Keys have been identified
Seagrass meadows are highly produc- as habitats for commercial 1y valuable spetive,
faunally rich, and ecologically cies, as well as for organi$ms that are
important habitats within south Florida's important trophic intermediaries. Many
estuaries and coastal lagoons (Figure 2) species are dependent on the bays, laas
we11 as throughout the world. The com- goons, and tidal creeks for she1 ter and
plex structure of the meadow represents food during a critical phase in their life
l iving space and protection from predation cycle.
for large populations of invertebrates and
fishes. The combination of plentiful shelter
and food results in seagrass meadows'
Many organisms that, are primarily
characterized by their presence and abunbeing
perhaps the richest nursery and
feeding grounds in south Florida's coastal
dance over coral reefs, such as the errormous
and colorful schools of snappers and
waters. As such, many commercially and grunts, are residents of the reef only by
ecological ly significant species within
mangrove, coral reef, and continental
day for the shel ter its camp1 ex structure
provides, foraging in adjacent grass beds
shelf communities are linked with seagrass at night. These seagrass meadows, often
beds,
located adjacent to the back reef areas of
barrfer reefs or surrounding patch reefs,
A1 though the importance of seagrass provide a rich feeding ground for diurnal
beds to shallow coastal ecosystems was reef residents; many of these organisms
demonstrated over 60 years ago by the may feed throughout their life cycle in
pioneering work of Petersen (119181 in the the grass bed. The juveniles of many
Baltic Sea, it is only in the past 10 to Pomadasyid species are resident in the
15 years that seagrasses have ~E?CO?W wfde- grass beds* As they grow, however, their
ly recognized as one of the richest of increasing size will no longer allow them
ecosystems, rivaling cu1 tivated tropical Po seek shel ter in the grass and they move
agriculture in productivitY ((Westlake on to the more complex structure of the
1963; Wood et a1. 1969; McRoy and McMillan reef for better protection (Qgden and
1977; Zieman and Wetzel 1980)~ Zieman 1977),
1