2015 Barnegat Bay Science Symposium 1
Benthic Community Structure as an Indicator of Habitat Quality
Gary Taghon, Judith Grassle, Charlotte Fuller, Rosemarie PetreccaDepartment of Marine and Coastal Sciences
2015 Barnegat Bay Science Symposium 2
Conclusions
Benthic invertebrate community in Barnegat Bay – Little Egg Harbor is healthy today
Benthic community largely unchanged from 40 years ago
2015 Barnegat Bay Science Symposium 3
Why use benthic invertebrates to infer habitat quality?
Most species are relatively sedentary, cannot avoid deteriorating conditions
Relatively long-lived, integrate habitat conditions over time
Different species have different tolerances to stress
Ecologically, play important roles in nutrient cycling and as prey
2015 Barnegat Bay Science Symposium 4
There are dozens of benthic indices of habitat quality
Used to classify sites along a gradient (bad/degraded to high/reference)
High/reference end usually means:
Minimally or least disturbed
Historical
Best attainable
Examples:
Benthic Index of Biotic Integrity (Weisberg et al. 1997)
Virginian Province Index (Paul et al. 2001)
Multivariate AZTI Marine Biotic Index (Borja et al. 2012)
Benthic Quality Index (Rosenberg et al. 2004)
2015 Barnegat Bay Science Symposium 5
What are indices based on?
Multivariate AZTI Marine Biotic Index (M-AMBI)
ParameterEffect on index
Species diversity Positive
Species richness Positive
Abundances of species in 5 categories from least to most sensitive to organic enrichment, based on expert opinion
Varies, 1 – 5
Developed for European coastal zones originally, now includes taxa from Virginian biogeographic province
Classifies habitat into one of five categories: bad, poor, moderate, good, high
2015 Barnegat Bay Science Symposium 6
HighGoodModeratePoorBad
2012 2013
Most of Barnegat Bay-Little Egg Harbor is classified presently as ‘good’ or ‘high’
M-AMBI class
2015 Barnegat Bay Science Symposium 7
2001 (EPA Regional Environmental Monitoring and Assessment Program)
Not random sampling design
How does benthic community in the present compare with the past?
HighGoodModeratePoorBad
M-AMBI class
‘Open bay’ stations
‘Marina’ stations
2015 Barnegat Bay Science Symposium 8
How does benthic community in the present compare with the past?
Five years of sampling, 1969-1973 (Loveland and Vouglitois 1984)
2015 Barnegat Bay Science Symposium 9
1969 1970 1971 1972 1973
Stouts Creek
Good High High High High
Forked River
Moderate High High High High
Oyster Creek
Moderate Good High High High
How does benthic community in the present compare with the past?
Classification by M-AMBI is similar to present day conditions
2015 Barnegat Bay Science Symposium 10
How does benthic community species composition and abundance in the past compare to the present?
Ampelisca
2015 Barnegat Bay Science Symposium 11
Ampelisca
How does benthic community species composition and abundance in the past compare to the present?
2015 Barnegat Bay Science Symposium 12
Sabaco
Pectinaria
How does benthic community species composition and abundance in the past compare to the present?
2015 Barnegat Bay Science Symposium 13
Mulinia
Turbonilla
How does benthic community species composition and abundance in the past compare to the present?
2015 Barnegat Bay Science Symposium 14
1972 2012 2013
Med
ian
par
ticl
e si
ze, µ
m
Tota
l vo
lati
le s
olid
s, %
How do sediment properties 40 years ago compare with the present?
1972 2012 2013
2015 Barnegat Bay Science Symposium 15
Sediment total organic C, %
<11-22-3>3
Today, most locations (67/100) in BB-LEH have low sediment organic carbon concentrations (<1% by mass)
2015 Barnegat Bay Science Symposium 16
Conclusions
Based on benthic community structure, the habitat quality of 92 of 100 locations throughout Barnegat Bay – Little Egg Harbor is presently categorized as Good to High
Locations sampled in 2001 in open parts of the bay were categorized as Moderate to High, while locations in or near marinas were categorized as Poor to High
Three locations sampled from 1969 to 1973 were categorized as Moderate to High; species present then are also present now in generally comparable abundances
The particle size and organic content of sediments does not appear to have changed appreciably over the last 40 years
