Chapter 25 Seagrass Conservation Biology
599
functions that do not have obvious immediate value
to society. Some services are deeply rooted in native cultures where ethnobotanists have identified
seagrass cultural values ranging from food to
medicine (Wyllie-Echeverria et al., 2000). Particular cultures have integrated seagrasses into their
traditional hunting and ceremonial life. These historical and cultural attributes provide an alternative
way of assigning conservation value to seagrass systems previously not emphasized in legal and judicial
processes. Simply stated, ‘people tend to conserve
what they cherish and use (Wyllie-Echeverria et al.,
2000).
E. Economic Value of the Seagrass Biome
The economic values of the seagrass biome are difficult to calculate within a traditional market analysis; however, Virnstein and Morris (1996) and
Costanza et al. (1997) provided what they described
as minimum estimates for seagrass and algal dominated systems. Based on published reports, Costanza
et al. (1997) assessed the annual value to be U.S.
$19,004 ha
−1 year
−1 , with primary value derived
from nutrient cycling and the supply of raw materials. Because this estimate does not include values associated with fishery stocks (spawning, rearing, and refuge habitat), the sustainability of marine
mammals, waterfowl, and turtles, beach protection,
or value associated with intrinsic worth, the figure
is an underestimate of actual worth. Based on fishery value alone, Virnstein and Morris (1996) estimated that the 80,000 acres (32,375 hectares) of seagrass in the Indian River Lagoon, Florida were worth
approximately one billion dollars (U.S. currency)
per year.
When seagrasses are damaged, restoration of the
seagrass biome is expensive and uncertain, and many
of the lost ecological services are not adequately restored (Fonseca et al., 1998; Fonseca et al., 2000a,
2002a). Replanting techniques have been used to a
limited extent for a small number of species, primarily Zostera marina, Thalassia testudinum, Halodule
wrightii, and Posidonia oceanica (Orth et al., 1994;
Molenaar and Meinesz, 1995; Balestri et al., 1998;
Fonseca et al., 1998), but documentation of success
is rare. Recent estimates for the cost for restoring
tropical seagrasses in the United States range from
approximately U.S. $100,000 per acre (0.4 hectares)
for moderate disturbances to as much as a million
dollars per acre in the worst cases where sediments
are physically disturbed. In most instances, the cost
of restoration and the assessments of success are
based on very small-scale projects. Probably, no one
has correctly estimated the cost of restoring an entire seagrass ecosystem or biome and even many of
the smaller scale attempts at restoration have failed
(Fonseca et al., 1998). The temptation to use replanting to justify new seagrass destruction underscores the urgency that such mitigation activities
must be closely monitored, controlled and prevented
unless they are deemed socially acceptable (Fonseca
et al., 1998; Fonseca et al., 2002a; Boudouresque,
2000). Successful seagrass restoration should be implemented with clearly defined objectives that measure success in regional and global terms (Campbell, 2000; den Hartog, 2000; Orth, 2000). For
example, a decision framework proposed for the
restoration of Posidonia oceanica in the Mediterranean region recommends only activities that are
initiated and completed by the use of a ‘code of
good conduct’ system emphasizing the point that
‘replanting cannot be done as compensation for deliberate seagrass destruction.’ The intrinsic value of
seagrasses, coupled with high restoration costs and
uncertainty of success, suggest that we prioritize the
benefit of conservation programs that minimize injuries to the seagrass biome and make every attempt
to avoid the expensive and uncertain repair of damaged ecosystems.
F. Cultural Value of the Seagrass Biome
Crustaceans, bivalves, egg masses, and fish associated with the seagrass biome have sustained and
continue to sustain coastal people in temperate and
tropical environments (Suttles, 1951; Felger and
Moser, 1985; Fortes, 1990; Kuhnlein and Turner,
1991; Wyllie-Echeverria et al., 2003; Bandeira and
Gell, 2003). Valued hunting and gathering sites are
often protected by cultural traditions nested within
mythological and social beliefs (e.g. Kurien, 1998;
Berkes et al., 2000). Food collected from these
sites supplements resources purchased in the marketbased economy (e.g. Turner et al., 2000). Seagrass
leaves from several species (Z. marina; Thalassodendron ciliatum; Enhalus acoroides; P. oceanica; Phyllospadix iwatensis; P. torreyi) are gathered
from the wrack line or cut above the surface of the
sediment, dried, and used for thatch, animal bedding, mattress and pillow stuffing, and cordage (Felger and Moser, 1985; Wyllie-Echeverria and Cox,
1999; Aioi and Nakaoka, 2003; Bandeira and Gell,
2003; Ochieng and Erftemeijer, 2003; Procaccini
599
functions that do not have obvious immediate value
to society. Some services are deeply rooted in native cultures where ethnobotanists have identified
seagrass cultural values ranging from food to
medicine (Wyllie-Echeverria et al., 2000). Particular cultures have integrated seagrasses into their
traditional hunting and ceremonial life. These historical and cultural attributes provide an alternative
way of assigning conservation value to seagrass systems previously not emphasized in legal and judicial
processes. Simply stated, ‘people tend to conserve
what they cherish and use (Wyllie-Echeverria et al.,
2000).
E. Economic Value of the Seagrass Biome
The economic values of the seagrass biome are difficult to calculate within a traditional market analysis; however, Virnstein and Morris (1996) and
Costanza et al. (1997) provided what they described
as minimum estimates for seagrass and algal dominated systems. Based on published reports, Costanza
et al. (1997) assessed the annual value to be U.S.
$19,004 ha
−1 year
−1 , with primary value derived
from nutrient cycling and the supply of raw materials. Because this estimate does not include values associated with fishery stocks (spawning, rearing, and refuge habitat), the sustainability of marine
mammals, waterfowl, and turtles, beach protection,
or value associated with intrinsic worth, the figure
is an underestimate of actual worth. Based on fishery value alone, Virnstein and Morris (1996) estimated that the 80,000 acres (32,375 hectares) of seagrass in the Indian River Lagoon, Florida were worth
approximately one billion dollars (U.S. currency)
per year.
When seagrasses are damaged, restoration of the
seagrass biome is expensive and uncertain, and many
of the lost ecological services are not adequately restored (Fonseca et al., 1998; Fonseca et al., 2000a,
2002a). Replanting techniques have been used to a
limited extent for a small number of species, primarily Zostera marina, Thalassia testudinum, Halodule
wrightii, and Posidonia oceanica (Orth et al., 1994;
Molenaar and Meinesz, 1995; Balestri et al., 1998;
Fonseca et al., 1998), but documentation of success
is rare. Recent estimates for the cost for restoring
tropical seagrasses in the United States range from
approximately U.S. $100,000 per acre (0.4 hectares)
for moderate disturbances to as much as a million
dollars per acre in the worst cases where sediments
are physically disturbed. In most instances, the cost
of restoration and the assessments of success are
based on very small-scale projects. Probably, no one
has correctly estimated the cost of restoring an entire seagrass ecosystem or biome and even many of
the smaller scale attempts at restoration have failed
(Fonseca et al., 1998). The temptation to use replanting to justify new seagrass destruction underscores the urgency that such mitigation activities
must be closely monitored, controlled and prevented
unless they are deemed socially acceptable (Fonseca
et al., 1998; Fonseca et al., 2002a; Boudouresque,
2000). Successful seagrass restoration should be implemented with clearly defined objectives that measure success in regional and global terms (Campbell, 2000; den Hartog, 2000; Orth, 2000). For
example, a decision framework proposed for the
restoration of Posidonia oceanica in the Mediterranean region recommends only activities that are
initiated and completed by the use of a ‘code of
good conduct’ system emphasizing the point that
‘replanting cannot be done as compensation for deliberate seagrass destruction.’ The intrinsic value of
seagrasses, coupled with high restoration costs and
uncertainty of success, suggest that we prioritize the
benefit of conservation programs that minimize injuries to the seagrass biome and make every attempt
to avoid the expensive and uncertain repair of damaged ecosystems.
F. Cultural Value of the Seagrass Biome
Crustaceans, bivalves, egg masses, and fish associated with the seagrass biome have sustained and
continue to sustain coastal people in temperate and
tropical environments (Suttles, 1951; Felger and
Moser, 1985; Fortes, 1990; Kuhnlein and Turner,
1991; Wyllie-Echeverria et al., 2003; Bandeira and
Gell, 2003). Valued hunting and gathering sites are
often protected by cultural traditions nested within
mythological and social beliefs (e.g. Kurien, 1998;
Berkes et al., 2000). Food collected from these
sites supplements resources purchased in the marketbased economy (e.g. Turner et al., 2000). Seagrass
leaves from several species (Z. marina; Thalassodendron ciliatum; Enhalus acoroides; P. oceanica; Phyllospadix iwatensis; P. torreyi) are gathered
from the wrack line or cut above the surface of the
sediment, dried, and used for thatch, animal bedding, mattress and pillow stuffing, and cordage (Felger and Moser, 1985; Wyllie-Echeverria and Cox,
1999; Aioi and Nakaoka, 2003; Bandeira and Gell,
2003; Ochieng and Erftemeijer, 2003; Procaccini