242
M. Sprung et al.
Photographs (1:10000 and 1:25000) were taken monthly during the vegetation period from April to October between 1988 and 1994. Simultaneously,
ground truth data were obtained by estimating dry weight and C-content of
above-ground biomass of subareas of 0.25m 2 • For each seagrass bed 4-5
samples were considered. Production of seagrasses was estimated by multiplying maximum seagrass biomass per area and a P/B max ratio of 10, as calculated for the subarea Konigshafen (Asmus 1984). For the Ria Formosa
lagoon estimates for the above-ground production of a Zostera noltii
meadow in the Palemones estuary (S. Spain) have been taken as reference
(Perez Llorens and NiellI993).
Green Algae. Because of its ephemeral occurrence, monthly increment in biomass has been used as the annual production parameter for the Ria Formosa
lagoon (AnfbalI998). In the Sylt-R0m0 Bay, green algae were registered by air
plane and by direct mapping in the field as described for Zostera beds, but
direct production measurements on green algae are missing in this area.
Phytoplankton. Production has been estimated by the oxygen dynamics in
dark and transparent bottles incubating for 6 h of daytime.
A comprehensive overview of methods and primary production rates of
different compartments of the Sylt -R0m0 Bay is given by Asmus et al. (1998).
11.3.2 Secondary Production
Macrobenthic secondary production data for different sites in the Sylt-R0m0
Bay have been published in Asmus and Asmus (1985), Asmus (1987) and
Asmus et al. (1998), and for intertidal sites of the Ria Formosa lagoon in
Sprung (1993, 1994a). Data have been - whenever possible - calculated by the
increment summation method between sample intervals of 4-6 weeks,
otherwise by PIB ratios calculated in most cases with the equation given by
Banse and Mosher (1980).
Secondary production of the salt marsh fauna of the Ria Formosa lagoon
has been extrapolated from abundance and body weight using PIB values
reported for similar species groups. The calculations are based on 54 core
samples of 113 cm 2 collected in spring and autumn 1997 and autumn 1999 in
the lower, central and higher marsh. In the Sylt-R0m0 Bay, secondary production of the marginal salt marshes was considered to be too low for
inclusion.
Feeding types have been attributed to species as published in Sprung
(1994a) and Asmus et al. (1998). In cases of more than one feeding mode
within species, it has been assumed that the species display these feeding
M. Sprung et al.
Photographs (1:10000 and 1:25000) were taken monthly during the vegetation period from April to October between 1988 and 1994. Simultaneously,
ground truth data were obtained by estimating dry weight and C-content of
above-ground biomass of subareas of 0.25m 2 • For each seagrass bed 4-5
samples were considered. Production of seagrasses was estimated by multiplying maximum seagrass biomass per area and a P/B max ratio of 10, as calculated for the subarea Konigshafen (Asmus 1984). For the Ria Formosa
lagoon estimates for the above-ground production of a Zostera noltii
meadow in the Palemones estuary (S. Spain) have been taken as reference
(Perez Llorens and NiellI993).
Green Algae. Because of its ephemeral occurrence, monthly increment in biomass has been used as the annual production parameter for the Ria Formosa
lagoon (AnfbalI998). In the Sylt-R0m0 Bay, green algae were registered by air
plane and by direct mapping in the field as described for Zostera beds, but
direct production measurements on green algae are missing in this area.
Phytoplankton. Production has been estimated by the oxygen dynamics in
dark and transparent bottles incubating for 6 h of daytime.
A comprehensive overview of methods and primary production rates of
different compartments of the Sylt -R0m0 Bay is given by Asmus et al. (1998).
11.3.2 Secondary Production
Macrobenthic secondary production data for different sites in the Sylt-R0m0
Bay have been published in Asmus and Asmus (1985), Asmus (1987) and
Asmus et al. (1998), and for intertidal sites of the Ria Formosa lagoon in
Sprung (1993, 1994a). Data have been - whenever possible - calculated by the
increment summation method between sample intervals of 4-6 weeks,
otherwise by PIB ratios calculated in most cases with the equation given by
Banse and Mosher (1980).
Secondary production of the salt marsh fauna of the Ria Formosa lagoon
has been extrapolated from abundance and body weight using PIB values
reported for similar species groups. The calculations are based on 54 core
samples of 113 cm 2 collected in spring and autumn 1997 and autumn 1999 in
the lower, central and higher marsh. In the Sylt-R0m0 Bay, secondary production of the marginal salt marshes was considered to be too low for
inclusion.
Feeding types have been attributed to species as published in Sprung
(1994a) and Asmus et al. (1998). In cases of more than one feeding mode
within species, it has been assumed that the species display these feeding