tion and nutrient regeneration phenomena
induced through direct grazing of living
macro algal tissues and particulate detritus processing (widely documented in the literature),
the present investigation highlights a further
aspect of the functional relationships established among biotic components in brackish
ecosystems. In fact, notwithstanding the large
body of information available on the effect of
water column chemical and physical characteristics on the development of Gracilaria spp.,
only scattered information is available on interactions with the macrofauna under field conditions (Brawley and Fei 1987).
In conclusion, our results suggest a potentially
effective control method on the quality of
Gracilaria, used worldwide as a commercial agar
source. The control on fouling phenomena in
seaweed mass cultivation through macro-organisms (i.e. fishes, Friedlander et al. 1996;
amphipods, Shaddock and Doyle 1983; isopods,
Shaddock 1992), in fact, is recognised as an
effective, alternative method to chemical
(Pickering et al.1993; Friedlander 1992; Haglund
and Pedersen 1993) and mechanical (PoIne et al.
1980) treatments. Our results may be of interest
for the development of highly productive, intensive and semi-intensive cultivations of G. verrucosa in the Lesina Lagoon.
Acknowledgements. This research was funded by the CNR
ISEC - Insitute for the Research on Coastal Ecosystems - to
G.M. We are grateful to Dr. Antonio Trombetta, Major of the
City of Lesina, for his strong support; to Dr. Paolo Villani.
director of the Institute for the Research on Coastal
Ecosystems, and to all the personnel at CNR ISEC for the help
provided at all stages of the investigation. This paper is dedicated to the memory of Prof. Giuseppe Magazzu.
References
Agnew DJ. Moore PG (1986) The feeding ecology of two littoral
amphipods (Crustacea), Echinogammarus pirloti (Sexton
and Spooner) and E. obtusatus (Dahl). J Exp Mar BioI Ecol
103:203-215
Arrontes J (1990) Diet, food preference and digestive efficiency in
intertidal isopods inhabiting macro algae. J Exp Mar BioI
Ecol139; 231-249
Brawley SH (1992) Mesoherbivores. In: John DM, Hawkins S1,
Price JH (eds) Plant-animal interactions in the marine benthos. Clarendon Press, Oxford, pp 235-263
Brawley SH, Fei XG (1987) Studies of mesoherbivory in aquaria
and unbarricaded maricolture farm on the chinese coast. J
Phyco123:614-623
Costantini ML. Rossi L (1995) Role of fungal patchiness on vegetal detritus in the trophic interactions between two brackish
Indirect Control ofVagile Epifauna on Gracilaria verrucosa
321
detritivores, Idotea baltica and Gammarus insensibilis.
Hydrobiologia 316: 117-126
D'Antonio C (1985) Epiphytes on the rocky intertidal red alga
Rhodomela larix (Turner) C. Agardth: negative effects on the
host and food for herbivoresf J Exp Mar Bioi Ecol 86: 197218
De Benedictis A, Cardellicchio N, Guarino SM, De Nicola M
(1996) Distribution of Fe. Zn, Cu and Cd in some organisms,
water and sediment of the Lake of Lesina (Southern Italy).
Ann Chim 86: 577-580
Dinardo C, Gambardella C, Guarino SM, De Nicola M (1997)
Reproductive biology of a Gammarus insensibilis Stock population living in the Lesina Lagoon. BioI Mar Medit 4: 377379
Duffy IE (1990) Amphipods on seaweeds: partners or pests?
Oecologia 83: 267-276
Friedlander M (1992) Gracilaria conferta and its epiphytes: the
effect of culture conditions on growth. Bot Mar 35: 423-428
Friedlander M, Weintraub N, Freedman A et aI. (1996) Fish as
potential biocontroller of Gracilaria (Rhodophyta) culture.
Aquaculture 145: 113-118
Frier JO (1979). Character displacement in Sphaeroma spp.
(Isopoda: Crustacea). 1. Field Evidence. Mar Ecol Prog Ser 1:
159-163
Haglund K, Pedersen M (1993) Outdoor pond cultivation of the
subtropical marine red alga Gracilaria tenuistipitata in
brackish water in Sweden. Growth, nutrient uptake, co-cultivation with rainbow trout and epiphyte control. J Appl
Phycol5: 271-284
Harrison PG (1977) Decomposition of macrophyte detritus in
seawater: effects of grazing by amphipods. Oikos 28: 165-169
Hay ME, Duffy JE, Pfister CA, Fenical W (1987). Chemical defense
against different marine herbivores: are amphipods insect
equivalents? Ecology 68: 1567-1580
Healy B, O'Neill M (1984) The life cycle and population dynamics
of Idorea pelagica and L granulosa (Isopoda: Valvifera) in
south-east Ireland. J Mar BioI Assoc UK 64: 21-33
Howard RK, Short FT (1986) Seagrass growth and survivorship
under the influence of epiphyte grazers. Aquat Bot 24: 287302
Kittlein MJ (1991) Population biology of Sphaeroma serratum
Fabricius (Isopoda, Flabellifera) at the Port of Mar del Plata,
Argentina. J Nat Hist 25: 1449-1459
lincoln RJ (1979). British Marine Amphipoda: Gammaridea.
British Museum (Nat Hist), London
Orth RI, Van Montfrans J (I984) Epiphyte-segrass relationships
with an emphasis on the role of micrograzing: a review.
Aquat Bot 18: 43-69
Pavia H, Carr H. Aberg P (1999) Habitat and feeding preferences
of crustacean mesoherbivores inhabiting the brown seaweeed Ascophyllum nodosum (L.) Le Jol and its epiphytic
macroalgae. J Exp Mar BioI Ecol 236: 15-32
Penniman CA, Mathieson AC, Penniman CE (1986) Reproductive
phenology and growth of Graci/aria tikvahiae McLachlan
(GigartinaIes, Rodophyta) in the Great Bay Estuary. New
Hampshire. Bot Mar 29: 147-154
Pickering TD. Gordon ME. Tong LJ (1993) Effect of nutrient pulse
concentration and frequency on growth of Gracilaria chilensis plants and levels of epiphytic algae. J Appl Phycol 5: 525533
Polne M, Gibor A, Neushul M (1980) The use of ultrasounds for
the removal of macro-algal epiphytes. Bot Mar 23: 731-734
Poore AGB (1994) Selective herbivory by amphipods inhabiting
the brown alga Zonaria angustata. Mar Ecol Prog Ser 107:
113-123
induced through direct grazing of living
macro algal tissues and particulate detritus processing (widely documented in the literature),
the present investigation highlights a further
aspect of the functional relationships established among biotic components in brackish
ecosystems. In fact, notwithstanding the large
body of information available on the effect of
water column chemical and physical characteristics on the development of Gracilaria spp.,
only scattered information is available on interactions with the macrofauna under field conditions (Brawley and Fei 1987).
In conclusion, our results suggest a potentially
effective control method on the quality of
Gracilaria, used worldwide as a commercial agar
source. The control on fouling phenomena in
seaweed mass cultivation through macro-organisms (i.e. fishes, Friedlander et al. 1996;
amphipods, Shaddock and Doyle 1983; isopods,
Shaddock 1992), in fact, is recognised as an
effective, alternative method to chemical
(Pickering et al.1993; Friedlander 1992; Haglund
and Pedersen 1993) and mechanical (PoIne et al.
1980) treatments. Our results may be of interest
for the development of highly productive, intensive and semi-intensive cultivations of G. verrucosa in the Lesina Lagoon.
Acknowledgements. This research was funded by the CNR
ISEC - Insitute for the Research on Coastal Ecosystems - to
G.M. We are grateful to Dr. Antonio Trombetta, Major of the
City of Lesina, for his strong support; to Dr. Paolo Villani.
director of the Institute for the Research on Coastal
Ecosystems, and to all the personnel at CNR ISEC for the help
provided at all stages of the investigation. This paper is dedicated to the memory of Prof. Giuseppe Magazzu.
References
Agnew DJ. Moore PG (1986) The feeding ecology of two littoral
amphipods (Crustacea), Echinogammarus pirloti (Sexton
and Spooner) and E. obtusatus (Dahl). J Exp Mar BioI Ecol
103:203-215
Arrontes J (1990) Diet, food preference and digestive efficiency in
intertidal isopods inhabiting macro algae. J Exp Mar BioI
Ecol139; 231-249
Brawley SH (1992) Mesoherbivores. In: John DM, Hawkins S1,
Price JH (eds) Plant-animal interactions in the marine benthos. Clarendon Press, Oxford, pp 235-263
Brawley SH, Fei XG (1987) Studies of mesoherbivory in aquaria
and unbarricaded maricolture farm on the chinese coast. J
Phyco123:614-623
Costantini ML. Rossi L (1995) Role of fungal patchiness on vegetal detritus in the trophic interactions between two brackish
Indirect Control ofVagile Epifauna on Gracilaria verrucosa
321
detritivores, Idotea baltica and Gammarus insensibilis.
Hydrobiologia 316: 117-126
D'Antonio C (1985) Epiphytes on the rocky intertidal red alga
Rhodomela larix (Turner) C. Agardth: negative effects on the
host and food for herbivoresf J Exp Mar Bioi Ecol 86: 197218
De Benedictis A, Cardellicchio N, Guarino SM, De Nicola M
(1996) Distribution of Fe. Zn, Cu and Cd in some organisms,
water and sediment of the Lake of Lesina (Southern Italy).
Ann Chim 86: 577-580
Dinardo C, Gambardella C, Guarino SM, De Nicola M (1997)
Reproductive biology of a Gammarus insensibilis Stock population living in the Lesina Lagoon. BioI Mar Medit 4: 377379
Duffy IE (1990) Amphipods on seaweeds: partners or pests?
Oecologia 83: 267-276
Friedlander M (1992) Gracilaria conferta and its epiphytes: the
effect of culture conditions on growth. Bot Mar 35: 423-428
Friedlander M, Weintraub N, Freedman A et aI. (1996) Fish as
potential biocontroller of Gracilaria (Rhodophyta) culture.
Aquaculture 145: 113-118
Frier JO (1979). Character displacement in Sphaeroma spp.
(Isopoda: Crustacea). 1. Field Evidence. Mar Ecol Prog Ser 1:
159-163
Haglund K, Pedersen M (1993) Outdoor pond cultivation of the
subtropical marine red alga Gracilaria tenuistipitata in
brackish water in Sweden. Growth, nutrient uptake, co-cultivation with rainbow trout and epiphyte control. J Appl
Phycol5: 271-284
Harrison PG (1977) Decomposition of macrophyte detritus in
seawater: effects of grazing by amphipods. Oikos 28: 165-169
Hay ME, Duffy JE, Pfister CA, Fenical W (1987). Chemical defense
against different marine herbivores: are amphipods insect
equivalents? Ecology 68: 1567-1580
Healy B, O'Neill M (1984) The life cycle and population dynamics
of Idorea pelagica and L granulosa (Isopoda: Valvifera) in
south-east Ireland. J Mar BioI Assoc UK 64: 21-33
Howard RK, Short FT (1986) Seagrass growth and survivorship
under the influence of epiphyte grazers. Aquat Bot 24: 287302
Kittlein MJ (1991) Population biology of Sphaeroma serratum
Fabricius (Isopoda, Flabellifera) at the Port of Mar del Plata,
Argentina. J Nat Hist 25: 1449-1459
lincoln RJ (1979). British Marine Amphipoda: Gammaridea.
British Museum (Nat Hist), London
Orth RI, Van Montfrans J (I984) Epiphyte-segrass relationships
with an emphasis on the role of micrograzing: a review.
Aquat Bot 18: 43-69
Pavia H, Carr H. Aberg P (1999) Habitat and feeding preferences
of crustacean mesoherbivores inhabiting the brown seaweeed Ascophyllum nodosum (L.) Le Jol and its epiphytic
macroalgae. J Exp Mar BioI Ecol 236: 15-32
Penniman CA, Mathieson AC, Penniman CE (1986) Reproductive
phenology and growth of Graci/aria tikvahiae McLachlan
(GigartinaIes, Rodophyta) in the Great Bay Estuary. New
Hampshire. Bot Mar 29: 147-154
Pickering TD. Gordon ME. Tong LJ (1993) Effect of nutrient pulse
concentration and frequency on growth of Gracilaria chilensis plants and levels of epiphytic algae. J Appl Phycol 5: 525533
Polne M, Gibor A, Neushul M (1980) The use of ultrasounds for
the removal of macro-algal epiphytes. Bot Mar 23: 731-734
Poore AGB (1994) Selective herbivory by amphipods inhabiting
the brown alga Zonaria angustata. Mar Ecol Prog Ser 107:
113-123