Lynn Ficarra
 “an increase in the rate of
supply of organic matter to
an ecosystem.” (Nixon 1995)
N&P
 land clearing, sewage, fertilizer, animals, fossil fuels,
industry
 Phytoplankton (Paerl 1988, Diaz and Rosenberg 2008)
 Block sun
 Die, sink to bottom, microbial respiration, hypoxia
Remove phytoplankton, nutrients, organic
materials, bacteria, and much much more!
(Ruesink et al. 2005, Gili and Coma 1998, Levinton 1972).
 Filtration rate
 Depends on species, size, water velocity, temperature
 Efficiency of particle retention
 Depends on filtering structure
(Comeau et al. 2008, Rice 2001, Eastern Oyster Biological Review Team 2007)
 Gills (Riisgard 1988)
 Parallel filaments
 Ciliary tracts: create current, capture particles
 Particles sorted (Newell 2004)
 Rejected: pseudofeces
 Digested: feces
 Mucus-coated aggregates
 Released to benthos
Filtration
Rate (Rank)
Retention of
Particles >4-5µm
Retention of
2µm Particles
Crassostrea virginica
(Eastern oyster)
1
100%
50%
Geukensia demissa
(Ribbed mussel)
2
100%
35-75%
Argopecten irradians
(Bay scallop)
2
100%
15%
Brachiodontes
exustus (Scorched
mussel)
3
100%
35-75%
Spisula solidissima
(Atlantic surfclam)
3
100%
35-75%
Mercenaria
mercenaria (Northern
Quahog)
4
100%
35-75%
Riisgard 1988
Capture Rate (mgC m-2d-1)
Aulacomya ater (mussel)
1787
Chlamys islandica (scallop)
3621
Crassostrea virginica (oyster)
573
Geukensia demissa (mussel)
30
Mercenaria mercenaria (quahog)
351
Ostrea edulis (oyster)
9-30
Gili and Coma 1998
 Mussels and eastern oysters performed well in
both studies
 Crassostrea virginicus and Mytilus edulis
 Native to east coast of U.S.
 Atlantic coast of U.S.
 0.6-5 m depth
 20-30°C optimal
 Survive freezing and >45°C, feeding rate affected
 Survive at salinities of 5-40 ppt
 Filtration rate up to 30-40 L h-1
 Create oyster reefs
 Promotes biodiversity
 Substrate for more suspension feeders
(Ruesink 2005, MacKenzie 1996, Stanley and Sellars 1986, Galtsoff 1964, Shumway 1996,
Eastern Oyster Biological Review Team 2007, Pechenik 2005)
 Coast of Canada to North Carolina
 1-10 m depth
 5-20°C optimal
 Survive freezing and up to 29°C
 >18 ppt ideal
 Survive low salinities 4-18 ppt, growth slowed
 Filtration rate 1.34-2.59 L h-1
 Mussel beds
 Increases biodiversity
 Substrate for more filter feeders
(Zagata et al. 2008, Goulletquer 2012, Bayne and Widdows 1978)
 Filtration rates at 9°C (Comeau et al. 2008)
 M. edulis: 1.82-2.90 L h-1
 C. virginica: 0.05-1.21 L h-1
 Optimal conditions: C. virginica faster than M.
edulis
 Cold conditions: M. edulis faster
 Use both for eutrophication control
 Average filtering rate at optimal conditions for 44
filter feeding species is 7.8 L g-1h-1 dry weight
(Pomeroy, D’Elia, and Schaffner 2006)
 Sponges (Milanese et al. 2003)
 retain up to 80% suspended particles
 Capture small particles that others miss (bacteria)
 Liverpool (Allen and Hawkins 1993)
 Mussels introduced to eutrophic water surrounding
docks
 Two years later water quality and oxygen levels in water
column and sediments improved
 Chesapeake Bay (Newell 1988)
 Pre-1870: oysters filter bay in 3-6 days
 Now: 325 days
 Competitive exclusion (Ruesink 2005)
 Toxic shellfish (MacKenzie et al. 2004)
 Invasive species (Ruesink 2005)
 Hitchhikers
 Pathogens (Moss et al. 2007)
 Asian oyster, Chesapeake Bay
 2 protist parasites not found in U.S. waters
 Viruses, cestodes, other protist parasites
Refer to Accompanying Paper