ArticlePDF Available

Evidence for intraspecific endocrine disruption of Geukensia demissa (Atlantic ribbed mussel) in an urban watershed

Authors:

Abstract and Figures

Populations undergo physiological adaptations in response to environmental stressors. Our five-year bio-monitoring study of the Bronx River Estuary demonstrates comparatively low dissolved oxygen concentrations in this urbanized watershed. Additionally, our current results establish altered hormonal levels, resulting from endocrine disruption, in Geukensia demissa (Atlantic ribbed mussel) from the Bronx River Estuary. No studies have yet investigated a correlation between low dissolved oxygen and endocrine disruption in field-collected bivalves. Testosterone, estradiol, and progesterone levels were collected from male and female mussels in the oxygen depleted Bronx River and well-oxygenated Greenwich Cove. Bronx River mussels exhibited higher testosterone levels and lower estradiol levels than Greenwich Cove mussels. The resulting abnormal hormonal ratio seems to indicate that environmental conditions in the Bronx River facilitate an allosteric inhibition of the cytochrome P450 aromatase enzyme, which aids conversion of testosterone to estradiol. Low progesterone levels suggest Bronx River mussels are experiencing a delay in sexual maturation, and morphometric data show a stalling of shell and tissue growth. To confirm that the mussels collected from both sites are the same species, the universal mitochondrial cytochrome c oxidase subunit I gene was analyzed, through DNA barcoding. Minimal sequential heterogeneity confirmed the mussels are the same species. Such findings suggest intraspecific divergence in various endocrine processes, resulting from environmentally induced stress.
Content may be subject to copyright.
Evidence for intraspecic endocrine disruption of Geukensia demissa
(Atlantic ribbed mussel) in an urban watershed
Zachery M. Halem, Dustin J. Ross, Rachel L. Cox
The Lisman Research Laboratories at Riverdale Country School, Bronx, NY, USA
abstractarticle info
Article history:
Received 15 October 2013
Received in revised form 28 April 2014
Accepted 30 April 2014
Available online 9 May 2014
Keywords:
COI gene
Dissolved oxygen
DNA barcoding
Endocrine disruption
Mussel
Populations undergo physiologica l adaptations in response to environm ental stressors. Our 5-year bio-
monitoring study of the Bronx River Estuary demonstrates comparatively low dissolved oxygen concentrations
in this urbanized watershed. Additionally, our current results establish altered hormonal levels, resulting from
endocrine disruption, in Geukensia demissa (Atlantic ribbed mussel) from the Bronx River Estuary. No studies
have yet investigated a correlation between low dissolved oxygen and endocrine disruption in eld-collected
bivalves. Testosterone, estradiol, and progesterone levels were collected from male and female mussels in the
oxygen depleted Bronx River and well-oxygenated Greenwich Cove. Bronx Riv er mussels exhibited higher
testosterone levels and lower estradiol levels than Greenwich Cove mussels. The resulting abnormal hormonal
ratio seems to indicate that environmental conditions in the Bronx River facilitate an allosteric inhibition of the
cytochrome P450 aromatase enzyme, which aids conversion of testosterone to estradiol. Low progesterone levels
suggest that Bronx River mussels are experiencing a delay in sexual maturation, and morphometric data show a
stalling of shell and tissue growth. To conrm that the mussels collected from both sites are the same species, the
universal mitochondrial cytochrome c oxidase subunit I gene was analyzed, through DNA barcoding. Minimal
sequential heterogeneity conrmed the mussels are the same species. Such ndings suggest intraspecic
divergence in various endocrine processes, resulting from environmentally induced stress.
© 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/3.0/).
1. Introduction
Endocrine disruption is hazardous to the vitality of any marine pop-
ulation. Numerous recent studies identify mechanisms and effects of
endocrine disruption in invertebrates. Vertebrate steroid hormones
(testosterone, estradiol, and progesterone) that are synthesized from
cholesterol are found in mollusks, and evidence shows that such sex ste-
roids can serve as ideal biomarkers of endocrine disruption (Gust et al.,
2010). While the specic function of steroid hormones in mollusks' en-
docrine system is still speculative, reports emphasize steroids' inuence
on gender differentiation, gametogenesis, gonadal maturation, fertiliza-
tion an d embryonic development, and reproduction (Mori, 1969;
Reis-Henriques and Coimbra, 1990; Matsumoto et al., 1997; Wang and
Croll, 2006; Ketata et al., 2008). Specically, testosterone and estradiol
concentrations in the gonads vary during different stages in the repro-
duction process, largel y affecting gender determination and gamete
growth (Matsumoto et al., 1997; Gauthier-Clerc et al., 2006). Progester-
one also inuences sex specic processes, such as gametogenesis and
gonadal development, and has been s hown to potentially impact
spawn ing in both sexes (Reis-Henriques and Coimbra, 1990; Wang
and Croll, 2006).
Endocrine disrupting compounds are frequently found in surface
water contamination, emanating from the sewage depositing of indus-
trial fa cilities (Gomes and Lester, 2003; Gültekin and Ince, 2007a,
2007b). Specic analysis of wastewater content through a hepatocyte
assay has shown industrially impacted water to possess estrogenic
activity (Islinger et al., 1999; Gagné and Blaise, 2000). Studies have
demonstrated that natural estrogens, such as 17β-estradiol, estriol and
estrone, ubiquitous in certain sewage efuents can induce a feminiza-
tion of sh (Björkblom et al., 2007). Certain heavy metals and chemicals
stimulate endocrine disruption in mollusks. Tributyltin (TBT) acts as a
neuro toxin and increases APGWamide, a neurotransmitter peptide,
which re leases the neurohormone Penis Morphogenic Factor (PMF)
(Oberdörster and McClellan-Green, 2000; Oberdörster et al., 2005;
Ketata et al., 2008). PMF generates male characteristi cs in both male
and female mollusks. However, no study has yet explored low dissolved
oxygen levels as an inducer of endocrine disruption in mollusks, or any
invertebrate.
Dissolved oxygen is vital for development, reproduction, and life in
nearly all aquatic organisms. The concentration of dissolved oxygen in
any given body of water is dependent on a multitude of factors, includ-
ing atmospheric reaeration, biochemical oxygen demand (BOD), the
Comparative Biochemistry and Physiology, Part A 175 (2014) 16
Corresponding author at: Riverdale Country School, 5250 Fieldston Road, Bronx, NY
10538, USA. Tel.: +1 718 549 8810x730.
E-mail address: rcox@riverdale.edu (R.L. Cox).
http://dx.doi.org/10.1016/j.cbpa.2014.04.016
1095-6433/© 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
Contents lists available at ScienceDirect
Comparative Biochemistry and Physiology, Part A
journal homepage: www.elsevier.com/locate/cbpa
organismal rate of cellular respiration, and the rate of photosynthesis
(Dobbins, 1965; Edwards and Owens, 1965; Bennett and Rathburn,
1972; Cox, 2003). Low dissolved oxygen results as a consequence of
processes that consume oxygen at a greater rate than processes that
produce oxygen (Rowe, 2001). In addition to natural regulators of
dissolved oxygen, eutrophication can articially reduce water's oxygen
content through runoff or sewage depositing. When dissolved oxygen
levels fall bel ow 23 mg/L, the water is identied as hypoxic, and
most organisms will struggle for survival (Diaz, 2001). Water that is
borderline hypoxic remains detrimental to organisms' physiological
processes (Diaz, 2001).
Urbanization and human industrial activity have a severe impact on
water quality and the health of estuarine ecosystems (Limburg et al.,
2005; Astaraie-Imani et al., 2012; Chin et al., 2013). Since industrializa-
tion, the Bronx River estuary, the only river to run through the city of
New York, remains a site of substantial sewage contamination (Wang
and Pant, 2010). The construction of the Bronx River Parkway in 1909
was the rst major disruption to the surrounding natural features.
This paralleling parkway reduced forest cover and contributed to poor
bank stabilization as urbanization grew dense (Rachlin et al, 2007).
The United States Environmental Protection Agency (EPA) labels path-
ogens as a major concern in the Bronx River, and speculates that CSOs
(combined sewer overow) are the likely source of such afiction
(Crimmens, T., 2002. Bronx River Restoration: Report and Assessment).
The New York City sewage system is designed to overow into nearby
rivers when waste is overly profuse. To date, the EPA has documented
31 causes of impairment in the Bronx River estuary, including patho-
genic contamination and oxygen depletion. The EPA has yet to indicate a
single cause of impairment for wildlife in the Greenwich Cove Estuary.
Despite various conservation efforts, our studies suggest that organ-
isms in the Bronx River are stressed, likely from persisting adverse envi-
ronmental conditions. Our research shows that the well-documented
stress responding protein, heat shock protein 70 (HSP70) displays
elevated baseline expression in Bronx River versus Greenwich Co ve
Geukensia demissa mussels as well as Spartina alterniora marsh grass
(Hans et al., 2013; Magun et al., 2013). In addition, our work indicates
that Bronx River mussels serve as a valuable in situ model to study the
potential synergistic effect of multiple active stress responders includ-
ing acetylcholinesterase and heat sh ock pr oteins 70 and 90 (Magun
et al., 2013). Most signicantly, our laboratory continues to document
lower dissolved oxygen levels in the Bronx Ri ver when compared to
Greenwich Cove (Shah et al., 2012).
To establish validity for our in situ study of comparative hormone
levels, we genetically conrmed the presence of Geukensia demissa
species in both sites by analyzing nucleotide divergence in cytochrome
c oxidase subunit I (COI) gene of the mitochondrial DNA, through DNA
barcoding. Since the 1990s, several systems have emerged for the iden-
tication of species (Sugita et al., 1998; Vincent et al., 2000; Floyd et al.,
2002). DNA barcoding emerged as a promising approach to make spe-
cies identication more quantitative for insects, and morphologically
challenging marine invertebrates, such as mollusks (Undheim et al.,
2010; Keskin and Atar, 2011). Conrmation that the populations from
Bronx River and Greenwich Cove are of the same species enables us to
infer that divergences in endocrine ratios are responses to the environ-
ment and not due to interspecic differences.
The current study demonstrates a correlation between comparative-
ly low dissolved oxygen levels in the Bronx River and endocrine
disruption in mussels from th at site. Further studies are required in
order to determine the mechanism responsible for this alteration. One
possibility is that low dissolved oxygen c oncentrations inhibit the
cytochrome P450 aromatase mediated conversion of testosterone to
estra diol, leading to a higher testosterone/es tradiol ratio in Bronx
River Geukensia demissa (Matthiessen and Gibbs, 1998; Alzieu, 2000;
Morcillo and Porte, 2000).
Another possibility is that energy limitations mediated by low dis-
solved oxygen and other factors such as food limitation delay growth
rate and maturation which could lead to altered levels of testosterone,
estradiol, and progesterone (Franz, 1996; Petes et al., 2007).
2. Materials and methods
2.1. Water analyses
Dissolved oxygen measurements were obtained using the Winkler
titration method. Oxygen was xed at each site using manganous
sulfate, alkaline potassium iodide azide, and sulfamic acid. Sodium thio-
sulfate was used to titrate the water sample with starch indicator to a
clear endpoint. pH measurements were collected using a Flinn Scientic
pH Meter (AP8673).
2.2. Sample collection and dissection
Geukensia demissa specimens were collected at low tide from Harding
Lagoon in the Bronx River (40° 48 35.563 N, 73° 51 40.893 W), and
Todd's Point in Greenwich Cove (4 0 31.296 N, 73° 34 18.042 W).
Our collections were performed during the months of June and July
when Geukensia demissa ranging in size from 25 to 36 mm (width) are
uniformly undergoing gametogenesis (Franz, 1996). Mussels were
transported to the laboratory in buckets with water collected from the
site. All samples, maintained in native water, were incubated at 4 °C
and allowed 24 h to equilibrate. The length, width, and total weight of
each mussel were recorded before dissection of tissues. Upon dissection,
shell weight and combined gill weight were also recorded. Both gills and
mantles were extracted from each organism, and stored at 20 °C.
2.3. Sex determination
Two tests were used to determine the sex of the mussels. Upon
dissection, the color of the mussels' mantle was noted. In Geukensia
demissa, a brown pigment signi
es a female, and a yellowish cre am
color is characteristic of males (Puglisi, 2008). For conrmation, the
mussel's gender was determined by the protocol of Jabbar and Davies
(1987) with slight mo dicati on. One mantle f rom each mussel was
placed in a Petri dish with 1 mL of 0.75% (w/v) thiobarbituric acid.
Males developed a yellow pigment, while females developed a pink
pigment. A 100% correlation was found between the results of the two
gender assays.
2.4. COI gene analysis
Genetic material was isolated from a 1 by 1 mm mantle sample from
12 organisms from each site (24 total) using the QIAGEN DNeasy Blood
and Tissue Kit (cat# 6904) and material was stored at 20 °C. PCR was
used to amplify the COI gene using Geukensia demissa specic primers:
5-CCGCGAATTAATAATTTCAGATTT-3/5-ACCAAAAAATCAAAATAAAT
GCAT-3. Primers were designed using GenBank Sequence
FJ693154
and synth esized by Sigma Genesis Inc. in a 5 μM concentration.
Twenty-ve microliters of PCR reactions, composed of 2 μL template
DNA and 11.5 μL of each primer in GE illustra PuReTaq Ready-To-Go
PCR Beads [cat# 27-9559-01], were subsequently prepared. Reactions
were run for 50 cycles with 30 s denaturation step at 94 °C, 45 s anneal-
ing step at 54 °C, and 45 s extending step at 72 °C using Techne Genius
Therm o Cycler. PCR products from the 24 individua ls produced
amplicons of approximately 440 bp as visualized on a 2% agarose gel
using pBR322/BstNI molecular weight standard from New England
Biolabs [cat #N2021L]. All products, along with Geukensia demissa cus-
tom primers, were sent to Genewiz I nc. for sequencing. Bronx River
and Greenwich Cove sequences were aligned by Nucleotide BLAS T,
and percent similarity was ascertained using the CLUSTAL W alignment
tool (Thompson et al., 1994; Ni et al., 2012).
2 Z.M. Halem et al. / Comparative Biochemistry and Physiology, Part A 175 (2014) 16
2.5. Testosterone, estradiol, and progesterone enzyme immunoassay (EIA)
Per each assay, one gill from each mussel was homogenized in
1.2 mL ice-cold 50:50 water:methanol. Homogenates were extracted
three times with 5 mL of high purity diethyl ether for the testosterone
assay, or 5 mL of dichloromethane for the estradiol and progesterone
assay. At room temperature, organic extracts were eva porated to
dryness. EIA buffer (500 μL; Cayman Chemical, Ann Arbor, MI, USA)
was used to reconstitute each sample.
Steroid hormones were quantied using commercial testosterone, es-
tradiol, and progestero ne enzyme immunoassay kits (Cayman Chemical,
cat#582701, 582251, 582601). The assay is based on the competitive
immunoreactions between the free hormone and steroid linked acetyl-
cholinesterase (AChE) conjugate for a nite amount of antiserum. EIAs
were performed in 96-well plate format, with each plate being read by
a Fisher Scientic* Multiskan* FC Microplate Reader (ca t# 14-387-360).
Standards, provided in each kit, were diluted to form standard curves
and assayed in duplicate on each plate. Testosterone standard concentra-
tions range from 500 to 3.9 pg/mL, estradiol standard concentrations
range from 6.6 to 4000 pg/mL, and progesterone standard concentrations
range from 7.8 to 1000 pg/mL. Two blank, two non-specic binding, three
maximum binding, and one total activity well(s) were also run on each
plate. Samples were run in triplicate at three dilutions: 1:1, 1:2, and
1:10. The intra- and inter-assay coefcients of variation (CVs) were less
than 10%. Cross reactivity of the testosterone antiserum with various ste-
roids is as follows: testosterone 100%, 5α-d ihydrot estoste rone 27.4%, 5β-
dihydrotestosterone 18.9%, methyltestosterone 4.7%, androstenedione
3.7%, 11-keto testosterone 2.2%, and lessthan1%forallothersteroidstest-
ed (Cayman Chemicals). Cross reactivity of the estradiol antiserum with
various steroids is as follows: estradiol 100%, estradiol-3-sulfate 14.5%,
estradiol-3-glucuronide 14%, estrone 12%, estradiol-17 glucuronide 10%,
and less than 0.5% for all other steroids tested (Cayman Chemicals).
Cross reactivity of the progesterone antiserum with various steroids is
as follows: progesterone 100%, 17β-estradiol 7.2%, 5β-Pregnan-3α-ol-
20-one 6.7%, pregnenolone 2.5%, and less than 1% for all other steroids
tested (Cayman Chemicals).
2.6. Statistical analyses
P-values for water data, morphometric data, and steroid hormone
concentrations were determined through a t-test. Any p-value less
than or equal to 0.05 is considered statistically signicant.
3. Results
3.1. Water analyses
Bronx River water has consistently possessed lower dissolved
oxygen concentrations than Greenwic h Cove over our 5-year study.
In the past 2 years, our show data has shown decreasing diss olved
oxygen concentrations in the Bronx River as a trend. Difference be-
tween the temperature and pH of the water at the two sites was mini-
mal (Table 1).
3.2. Morphometric data
Bronx River mussels were consistently of smaller size (length/width)
and lower weight than Greenwich Cove mussels over our 5-year study.
Average combined gill weight was also signicantly lower in Bronx
River mussels.
3.3. COI gene analysis
Among Bronx River mussels, CLUSTAL W alignment revealed negli-
gible heterogeneity (01%) in COI sequence. CLUSTAL W alignment
also showed insignicant (01%) divergence in COI sequence within
the Greenwich Cove population. When compared across sites, however,
alignment disclosed a consistent 2% sequential heterogeneity. Organism
gender appeared to have no impact on COI gene sequence.
3.4. Tissue steroid levels
Steroid levels were determined in gill tissue. The same mussel test
cohort was used for the testosterone and estradiol assays, but different
individuals were used for progesterone assay. Testosterone concentra-
tions were signicantly higher (p b 0.05) in Bronx River mussels rela-
tive to Greenwich Cove mussels (2.1 fold in males, 3.6 fold in females)
(Fig. 1A). In both sites, male mussels contained higher levels of testos-
terone than female mussels. The Bronx River mussels also possessed
Table 1
Average levels of dissolved oxygen levels (mg/L), water temperature (°C), and pH, over a
5-year survey of the Bronx River and Greenwich Cove.
Site Dissolved oxygen (mg/L) Temperature (°C) pH
Bronx River 3.9 ± 0.2 22.35 ± 0.24 7.29 ± 0.02
Greenwich Cove 10.0 ± 0.7 25.32 ± 0.94 7.97 ± 0.07
All water collections (3 each year) occurred in June and July, around low tide. Data are
presented as mean ± SEM (n = 15). p b 0.0001 for dissolved oxygen concentrations.
Male
Female
Male Female
Male Female
0
50
100
150
200
Bronx River Greenwich Cove
pg/ml testosterone
A
0
20
40
60
80
100
0
20
40
60
80
100
120
Bronx River Greenwich Cove
pg/ml estradiol
B
Bronx River Greenwich Cove
pg/ml progesterone
C
Fig. 1. Gill steroid hormone concentrations (pg/mL) for (A) testosterone, (B) estradi-
ol, and (C) progesterone. Male and female distinctions ar e presented. Data are shown
as mean ± SEM (n =16,8males,8females).p = 0.00885 for testosterone, p =
0.04175 for estradiol, and p = 0.0001 for progesterone.
3Z.M. Halem et al. / Comparative Biochemistry and Physiology, Part A 175 (2014) 16
lower estradiol concentrations than Greenwich Cove mussels (Fig. 1B).
Female mussels had higher tiss ue concentrations of estradiol than
male mussels at the Bronx River (57.6 ± 1.6 pg/mL versus 14.1 ±
0.8 pg/mL) and Greenwich Cove (86.4 ± 3.1 pg/mL versus 25.9 ±
2.5 pg/mL). Thus, the testosterone/estradiol ratio (combining concen-
trations in male and female mussels) is signicantly higher in Bronx
River mussels (3.60) than Greenwich Cove mussels (0.93). Progesterone
levels were not inuenced by gender, but varied between the two sites.
The concentration was higher in gill tissue of Greenwich Cove mussels
than Bronx River mussels (6.6- and 4.3-fold for male and female,
respectively) (Fig. 1C).
4. Discussion
Results of our comparative steroid a nalysis suggest that mussels
living in an urbanized and environmentally impacted watershed are
experiencing endocrine disruption, indicated by the relative concentra-
tions of all three endogenous steroids (testo sterone, estradiol, and
progesterone). The Bronx River mussels have signicantly higher tes-
tosterone levels (2.1 fold in males, 3.6 fold in females) and signicantly
lower estradiol concentrations (1.8 fold in males, 1.5 fold in females)
(Fig. 1A). The average ratio of testosterone/estradiol (pg/mL) is 3.60 in
Bronx River mussels, juxtaposed to the normal 0.93 in Greenwich
Cove mussels.
Our ndings concur with Friesen et al. (2012) and other recent stud-
ies that correlate low dissolved oxygen with endocrine disruption in sh
species (Wu et al., 2003; Landry et al., 2007). The pathway for such an
alteration was identied as a hypoxia mediated inhibit ion of cyto-
chrome P450 aromatase activity (Alzieu, 2000; Matthiessen and Gibbs,
1998; Morcillo and Porte, 2000; Shang et al., 2006). This mechanism
may explain our observed alterations of the testosterone/estradiol
ratio in mussels from the oxygen depleted Bronx River. Such an inhibi-
tion could lead to a general masculini zation of both male and female
mussels, though more research is required.
Evidence also shows that low dissolved oxygen can impact growth
and development, RNA/DNA ratio, gonad and embryo formation,
tness, and survival rates in sh species (Zhou et al., 2001; Gercken
et al., 2006; Hassell et al., 2008; Kolding et al., 2008; Wang et al.,
2008). These ndings correlate well with our 5-year morphometric
studies demonstrating that Geukensia demissa from the hypoxic Bronx
River site have a consistently lower body mass index than ribbed
mussels from Greenwich Cove, CT.
In addition, studies show that heavy metals, specically tributyltin
(TBT) inhibit cytochrome P450 aromatase, thus blocking the conversion
of testosterone to estradiol, and affecting the testosterone/estradiol ratio
(Matthiessen and Gibbs, 1998; Alzieu, 2000; Morcillo and Porte, 2000).
Other substances known to induce endocrine disruption and the
conversion of testosterone to estradiol in marine inv ertebrates include:
herbicides (diquat dibromide, atrazine, simazine, diuron), metals (cadmi-
um, selenium, zinc, mercury, lead), PCBs, alkylphenols (nonylphenol,
pentylphenol), and insecticides (DDT, ednrin, toxaphene, piperonyl
butoxide, methoprene) (Depledge and Billinghurst , 1999).
Endocrine disruption is also indicated by the signicantly low level
of progesterone in the gill tissue of Bronx River mussels averaging
18.6 ± 1.3 pg/mL, as compared to an average of 98.6 ± 1.9 pg/mL in
Greenwich Cove mussels. Conditions in the Bronx River could potential-
ly alter energy demands of the mussels, forcing them to distribute the
limited available oxygen towards aerobic metabolic processes, rather
than the synthesis of progesterone. Our conclusion that progesterone
levels are not gender mediated supports the hypothesis of Reis-
Henriques and Coimbra (1990), which indicates that male and female
mussels require a similar pattern and amount of progesterone through-
out their reproductive cycle. We expect the progesterone deciency to
have other physiological effects. During the maturation of oocytes in
M. edulis, an increase in ly sosomal enzyme activity is usually noted
(Peek and Gabott, 1990). In correlation, rising progesterone levels in
M. edulis have been shown to result in the destabilization of lysosomes
(Moore et al., 1978). Thus, studies suggest progesterone as a biomarker
of sexual maturation, in regard to oocyte progression (Siah et al., 2003).
Moreover, st udies show that progesterone levels peak during active
gametogenesis, when the male's gonads are maturing and females are
in the spawning stage (Reis-Henriques and Coimbra, 1990; Siah et al.,
2002). Due to a lack of progesterone, the Bronx River mussels may be
undergoing a deceleration of the rate of sexual maturation and oocyte
development. In addition, progesterone has shown to act as a gonad
messenger for neurohor mones (Siah et al., 2002). The Bronx River
mussels may be experiencing a de lay in germ cell proliferation, and
our results lead us to hypothesize that the lack of progesterone has
affected the production of neurohormones. To conrm this hypothesis,
further studies will be required to examine neurohormone-receptor
responses to oxygen depletion.
COI gene analysis revealed only slight heterogeneity for organisms
from the same site (01% Bronx, 01% Greenwich), thus indicating
that mussel populations at both sites contain only one species. The 2%
COI sequen ce divergence when comparing mussels across sites indi-
cates that mussels at both sites ar e of the same sp ecies (Geukensia
demissa). This supports the claims of Hebert et al. (2003) that for two
populations, intraspeci c COI sequence divergence is approximately
2% (Avise, 2000; Cognato, 200 6). The consistent 2% heterogeneity in
COI sequence across sites indicates adaptive pressure, indicating the
possibility of allopatric speciation in the future.
As mentioned above, morphometric analysis demonstrates a
delayed shell growth and tissue growth in Bronx River mussels
(Table 2). The growth rate of mussels tends to vary by season, higher
in spring and summer, and lower in winter (Page and Hubbard, 1987;
Garen et al., 2004). In addition, shell and tissue growth are generally af-
liated with the reproductive cycle of the given population (Bayne and
Worrall, 1980; Handå et al., 2011). However, in mussels, shell growth is
not directly correlated to tissue growth (Hilbish, 1986; Kautsky, 1982;
Rodhouse et al., 1984). Environmental stress and food limitations are
known to impede growth processes. The 31 causes of impairment (as
documented by the EPA) or the limitation of dissolved oxygen in the
Bronx River may require that mussels conserve energy for vital survival
processes, which would delay shell and tissue growth. A recent study
transplanted Mytilus galloprovincialis and Perna c analiculus to high-
Table 2
Average body mass, condition index (CI) total ((wet weight / total weight) × 100), CI shell ((wet weight / shell weight) × 100), and combined gill weight in Geukensia demissa mussels
taken over a 5-year span from the Bronx River and Greenwich Cove (Shah et al., 2012).
Bronx River Greenwich Cove
2009 2010 2011 2012 2013 2009 2010 2011 2012 2013
Length/Width (mm) 66.6/28.4 60.0/24.0 62.0/27.3 ND 72.8/30.9 77.0/31.1 85.0/31.0 81.1/32.6 ND 86.2/40.2
Average body mass (g) 17.5 18.16 20.39 30.1 37.80 21.8 35.88 36.03 39.7 46.76
Conditionindextotal 44414838424144514358
Condition index shell 84 72 89 63 79 74 80 106 76 89
Average combined gill mass (g) 0.87 1.08 0.80 ND 0.97 1.33 1.30 1.13 ND 1.21
ND = no data available.
p = 0.0099 for length, and p = 0.0150 for average combined gill mass.
4 Z.M. Halem et al. / Comparative Biochemistry and Physiology, Part A 175 (2014) 16
stress and low-stress elevation edges of an intertidal mussel bed to com-
pare growth and reproduction (Petes et al., 2007). Mussels living in the
high-stress edge exhibited reduced growth rate and a smaller tissue
mass (Petes et al., 2007). Additional studies demonstrate endogenous
steroid levels as regulators of growth. In the fresh water mussel, Elliptio
complanata (Gagné et al., 2001) demonstrated that high estrogen levels
promote total and soft tissue weights. The lack of estradiol in Bronx
River mussels may have stunted tissue growth, accounting for the re-
duced average total body weight and average combined gill weight
(Table 2).
5. Conclusion
Overall, this study is the rst to demonstrate a correlation between
low dissolved oxygen emanating from an urbanized site and disruption
in endogenous steroid levels, physiological development, and sexual
maturation in Geukensia demissa.
Acknowledgments
We wish to acknowledge the Marjot Foundation and Riverdale
Country School for generous support of our research. We thank Eli
Sands and all of the researchers at the Lisman Research Laboratories
for their invaluable assistance. We wish to express additional gratitude
towards Kelley Nicholson-Flynn for editorial assistance and Kevin Bailey
for assistance with statistical analyses.
References
Alzieu, C., 2000. Impact of tributyltin on marine invertebrates. Ecotoxicology 9, 7176.
Astaraie-Imani, M., Kapelan, Z., Fu, G., Butler, D., 2012. Assessing the combined effects of
urbanisation and climate change on the river water quality in an integrated urban
wastewater system in the UK. J. Environ. Manag. 112, 19.
Avise, J.C., 2000. Phylogeography. The History and Formation of Species, Harvard University
Press, Cambridge, MA.
Bayne, B.L., Worrall, C.M., 1980. Growth and production of mussels Mytilus edulis from
two populations. Mar. Ecol. Prog. Ser. 3, 317328.
Bennett, J.P., Rathburn, R.E., 1972. Reaeration in open-channel ow. USGS Professional
paper, 737, pp. 175.
Björkblom, C., Olsson, P.-E., Katsiadaki, I., Wiklund, T., 2007. Estrogen- and androgen-
sensitive bioass ays based on primary cell and tissue slice cultures from three-
spined stickleback (Gasterosteus aculeatus). Comp. Biochem. Physiol. C 146, 431442.
Chin, A., O'Dowd, A.P., Gregory, K.J., 2013. 9.39 Urbanization and river channels. Treatise
Geomorphol. 9, 809827.
Cognato, A.I., 2006. Standard percent DNA sequence difference for insects does not
predict specic boundaries. J. Econ. Entomol. 99 (4), 10371045.
Cox, B.A., 2003. A review of dissolved oxygen modelling techniques for lowland rivers. Sci.
Total Environ. 314316, 303334.
Crimmens, T., 2002. Bronx River Watershed Assessment and Management Report, Bronx
River Alliance (http://www.westchestergov.com/planning/envir onmental/BronxRiver/
Management%20Plan.htm).
Depledge, M.H., Billinghurst, Z., 1999. Ecological signicance of endocrine disruption in
marine invertebrates. Mar. Pollut. Bull. 39 (112), 3238.
Diaz, R.J., 2001. Overview of hypoxia around the world. J. Environ. Qual. 30 (2), 275281.
Dobbins, W.E., 1965. BOD and oxygen relationships in streams. J. Sanit. Eng. Div. 90 (3),
5378.
Edwards, R.W., Owens, M., 1965. The oxygen balance of streams. Ecol. Industr. Soc. 5,
149172.
Floyd, R., Abebe, E., Papert, A., Blaxter, M., 2002. Molecular barcodes for soil nematode
identication. Mol. Ecol. 11, 839850.
Franz, D.R., 1996. Size and age at rst reproduction of the ribbed mussel Geukensia
demmissa (Dillwyn) in relation to shore level in a New York salt marsh. J. Exp. Mar.
Biol. Ecol. 205 (12), 113.
Friesen, C.N., Aubin-Horth, N., Chapman, L.J., 2012.
The effect of hypoxia on sex hormones
in an African cichlid Pseudocrenilabrus multicolor victoria. Comp. Biochem. Physiol. A
162 (1), 2230.
Gagné, F., Blaise, C., 2000. Evaluation of environmental estrogens with a sh cell line. Bull.
Environ. Contam. Toxicol. 65, 494500.
Gagné, F., Blaise, C., Salazar, M., Salazar, S., Hansen, P.D., 2001. Evaluation of estrogenic
effects of municipal efuents to the freshwater mussel Elliptio complanata. Comp.
Biochem. Physiol. C 128 (2), 213225.
Garen, P., Robert, S., Bougrier, S., 2004. Comparison of growth of mussel, Mytilus edulis,on
longline, pole and bottom culture sites in the Pertuis Breton, France. Aquaculture 232,
511524.
Gauthier-Clerc, S., Pellerin, J., Amiard, J.C., 2006. Estradiol-17β and testosterone concen-
trations in male and female Mya arenaria (Mollusca bivalvia) during the reproductive
cycle. Gen. Comp. Endocrinol. 145, 133139.
Gercken, J., Forlin, L., Andersson, J., 2006. Developmental disorders in larvae of eelpout
(Zoarces viviparus) from German and Swedish Baltic coastal waters. Mar. Pollut.
Bull. 53, 497507.
Gomes, R.L., Lester, J.N., 2003. Endocrine disruptors in receiving waters. Endocrine
Disruptors in Wastewater and Sludge Treatment Processes, 6, pp. 177217.
Gültekin, I., Ince, N.H., 2007a. Synthetic endocrine disruptors in the environment and
water remediation by advanced oxidation processes. J. Environ. Manag. 85, 816832.
Gültekin, I., Ince, N.H., 2007b. Synthetic endocrine disruptors in the environment and
water remediation by advanced oxidation processes. J. Environ. Manag. 85, 816832.
Gust, M., Vulliet, E., Giroud, B., Garnier, F., Couturier, S., Garric, J., Buronfosse, F., 2010. De-
velopment, validation and comparison of LC-MS/MS and RIA methods for quantica-
tion of vertebrates-like sex-steroids in prosobranch molluscs. J. Chromatogr. B 878
(19), 14871492.
Handå,A.,Alver,M.,Edvardsen,C.V.,Halstensen,S.,Olsen,A.J.ie,G.,Reitan,K.I.,Olsen,Y.,
Reinertsen, H., 2011. Growth of farmed blue mus sels ( Mytilus edulis L.) in a
Norwegian coastal area; comparison of food proxies by DEB modeling. J. Sea
Res. 66 (4), 297307.
Hans, M., Falkner, P., Magun, H., Kelemen, S., 2013. Differential Expression of Heat Shock
Protein 70 in Spartina alterniora in an Environmentally Impacted Salt Marsh Estuary.
Abstract. American Association Advancement of Science, Boston, MA.
Hassell, K.L., Coutin, P.C., Nugegoda, D., 2008. Hypoxia impairs embryo development and
survival in black bream (Acanthopagrus butcheri). Mar. Pollut. Bull. 57, 302306.
Hebert, P.D.N., Cywinska, A., Ball, S.L., deWaard, J.R., 2003. Biologica l identications
through DNA barcodes. Proc. R. Soc Lond. Biol. Sci. 270, 313321.
Hilbish, T.J., 1986. Growth trajectories of shell and soft tissue in bivalves: seasonal varia-
tion in Mytilus edulis L. J. Exp. Mar. Biol. Ecol. 96, 103113.
Islinger, M., Pawlowski, S., Hollert, H., Volkl, A., Braunbeck, T., 1999. Measurement of vitel-
logenin-mRNA expression in primary cultures of rainbow trout hepatocytes in a non-
radioactive dot blot/RNAse protection-assay. Science Total Envir. 233, 109122.
Jabbar, A., Davies, J.I., 1987. A simple and convenient biochemical method for sex identi-
cation in the marine mussel, Mytilus edulis L. J. Exp. Mar. Biol. Ecol. 107 (1), 3944.
Kautsky, N., 1982. Growth and size structure in a Baltic Mytilus edulis population. Mar.
Biol. 68, 117133.
Keskin, E., Atar, H.H., 2011. Genetic divergence of Octopus vulgarisspecies in the eastern
Mediterranean. Biochem. Syst. Ecol. 39 (46), 227282.
Ketata, I., Denier, X., Hamza-Chaffai, A., Minier, C., 2008. Endocrine-related reproductive
effects in molluscs. Comp. Biochem. Physiol. C 147 (3), 261270.
Kolding, J., Haug, L., Stefansson, S., 2008. Effect of ambient oxygen on growth and re- pro-
duction in Nile tilapia (Oreochromis niloticus). Can. J. Fish. Aquat. Sci. 65, 14131424.
Landry, C.A., Steele, S.L., Manning, S., Cheek, A.O., 2007. Long term hypoxia suppresses re-
productive capacity in the estuarine sh, Fundulus grandis. Comp. Biochem. Physiol. A
148, 317323.
Limburg, K.E., Stainbrook, K.M., Erickson, J.D., Gowdy, J.M., 2005. Urbanization conse-
quences: case studies in the Hudson River watershed. Am. Fish. Soc. Symp. 47, 2337.
Magun, H., Mills, A., Vaccaro, D., 2013. Characterization of Stress-Responding Protein
Expression in Heat Shocked Marine Molluscs: Potential Model for the Response
of Acetyl-Choline Esterase to Heat. Abstract. American Association Advancement of
Science, Boston, MA.
Matsumoto, T., Osada, M., Osawa, Y., Mori, K., 1997. Gonadal estrogen prole and immu-
nohistochemical localisation of ste roidogenic enzyme s in the oy ster and scallop
during sexual maturation. Comp. Biochem. Physiol. B 118, 811817.
Matt hiessen, P., Gibbs, P. E., 1998. Critical appraisal of the evidence for tributyltin-
mediated endocrine disruption in mollusks. Environ. Toxicol. Chem. 17, 3743.
Moore, M.N., Lowe, D.M., Fieth, P.E.M., 1978. Responses of lysosomes in the digestive cells
of the common mussel, Mytilus edulis, to sex steroids and cortisol. Cell Tissue Res.
188, 19.
Morcillo, Y., Porte, C., 2000. Evidence of endocrine disruption in clamsRuditapes decus-
satetransplanted to a tributyltin-polluted environment. Environ. Pollut. 107, 47
52.
Mori, K., 1969. Effect of steroid in oyster-IV. Acceleration of sexual maturation in female
Crassostrea gigas by estradiol-17β. Bull. Jpn Soc. Sci. Fish. 35, 10771079.
Ni, L., Li, Q., Kong, L., Huang, S., Li, L., 2012. DNA barcoding and phylogeny in the family
Mactridae (Bivalvia Heterodonta): evidence for cryptic species. Biochem. Syst. Ecol.
44, 164172.
Oberdörster, E., McClellan-Green, P., 2000. The neuropeptide APGWamide induces
imposex in the mud snail, Ilyanassa obsolete. Peptides 21, 13231330.
Oberdörster, E., Romano, J., McClellan-Green, P., 2005. The neuropeptide APGWamide as a
penis morphogenic factor (PMF) in gastropod mollusks. Integr. Comp. Biol. 45 (1),
2832.
Page, H.M., Hubbard, D.M., 1987. Temporal and spatial patterns of growth in mussels
Mytilus edulis on an offshore platform: relationships to water temperature and food
availability. J. Exp. Mar. Biol. Ecol. 111, 159179.
Peek, K., Gabott, P.A., 1990. Seasonal cycle of lysosomal enzyme activities in the mantle
tissue and isolated cells from the mussel Mytilus edulis. Mar. Biol. 104, 403412.
Petes, L. E., Menge, B.A., Murphy, G.D., 2007. Environmental stress decreases survival,
growth, and reproduction in New Zealand mussels. J. Exp. Mar. Biol. Ecol. 351
(12), 8391.
Puglisi, M.P., 2008. Geukensia demissa: Atlantic Ribbed Mussel. Smithsonian Marine
Station at Fort Pierce. http://www.sms.si.edu/irlspec/Geukensia_demissa.htm.
Rachlin, J.W., Warkentine, B.E., Pappantoniou, A., 2007. An evaluation of the ichthyofauna
of the Bronx River, a resilient urban waterway. Northeast. Nat. 14, 531544.
Reis-Henriques, M.A., Coimbra, J., 1990. Variations in the levels of progesterone in Mytilus
edulis during the annual reproductive cycle. Comp. Biochem. Physiol. A 95, 343348.
Rodhouse, P.G., Roden, C.M., Hensey, M.P., Ryan, T.H., 1984. Resource allocation in Mytilus
edulis on the shore and in suspended culture. Mar. Biol. 84, 2734.
Rowe, G.T., 2001. Seasonal hypoxia in the bottom water off the Mississippi Delta. J. Environ.
Qual. 30 (2), 281290.
5Z.M. Halem et al. / Comparative Biochemistry and Physiology, Part A 175 (2014) 16
Shah, J., Levine, J., Magun, H., Garcia-Sanabria, N., Yagi, D., Para, S., Dewees, N., Kelemen, S.,
2012. Effect of Heat Shock on Acetylcholine Esterase Activity in Atlantic Ribbed
Mussel (G. demissa). Abstract, A merican Association Advancement of Science,
Vancouver, BC.
Shang, E.H.H., Yu, R.M.K., Wu, R.S.S., 2006. Hypoxia affects sex differentiation and devel-
opment, leading to a male-dominated population in zebrash (Danio rerio). Environ.
Sci. Technol. 40, 31183122.
Siah, A., Pellerin, J., Benosman, A., Gagné, J.P., Amiard, J.C., 2002. Seasonal gonad progesterone
pattern in the soft-shell clam Mya arenaria. Comp. Biochem. Physiol. A 132 (2),
499511.
Siah, A., Pellerin, J., Amiard, J.C., Pelletier, E., Viglino, L., 2003. Delayed gametogenesis and
progesterone levels in soft-shell clams (Mya arenaria) in relation to in situ contami-
nation to organotins and heavy metals in the St. Lawrence River (Canada). Comp.
Biochem. Physiol. C 135 (2), 145156.
Sugita, T., Nishikawa, A., Shinoda, T., 1998. Identication of Trichosporon asahii by PCR
based on sequences of the internal transcribed spacer regions. J. Clin. Microbiol. 36,
27422744.
Thompson, J.D., Higgins, D.G., Gibson, T.J., 1994. CLUSTAL W: improving the sensitivity of
progressive multiple sequence alignment through sequence weighting, positions-
specic gap penalties and weight matrix choice. Nucleic Acids Res. 22, 46734680.
Undheim, E.A., Normanb, A.N., Thoen, H.H., Fry, B.G., 2010. Genetic identication of South-
ern Ocean octopod samples using mtCOI. C. R. Biol. 333, 395404.
Vincent, S., Vivian, J.M., Carlotti, M.P., 2000. Partial sequencing of the cytochrome oxidase-
b subunit gene I: a tool for the identication of European species of blow ies for post
mortem interval estimation. J. Forensic Sci. 45, 820823.
Wang, C., Croll, R.P., 2006. Effects of sex steroids on spawning in the sea scallop,
Placopecten magellanicus. Aquaculture 256, 423432.
Wang, S., Yuen, S., Randall, D., Hung, C., Tsui, T., Poon, W., Lai, J., Zhang, Y., Lin, H., 2008.
Hypoxia inhibits sh spawning via LH-depen dent nal oocyte maturation. Comp.
Biochem. Physiol. C 148, 363369.
Wang, J., Pant, H.K., 2010. Enzymatic hydrolysis of organic phosphorus in river bed sedi-
ments. Ecol. Eng. 36 (7), 963968.
Wu, R.S.S., Zhou, B.S., Randall, D.J., Woo, N.Y.S., Lam, P.K.S., 2003. Aquatic hypoxia is an en-
docrine disruptor and impairs sh reproduction. Environ. Sci. Technol. 37,
11371141.
Zhou, B.S., Wu, R.S.S., Randall, D.J., Lam, P.K.S., 2001. Bioenergetics and RNA/DNA ratios in
the common carp (Cyprinus carpio) under hypoxia. Comp. Biochem. Physiol. B 171,
4957.
6 Z.M. Halem et al. / Comparative Biochemistry and Physiology, Part A 175 (2014) 16
... The Bronx River Estruary's native molluscan species Geukensia demissa (G. demissa) exhibits endocrine disruption and stunted growth (Halem et al., 2014). In addition, the foundational species Spartina alterniflora demonstrates elevated levels of the stress protein heat shock protein 70 (Hsp70), which is indicative of an adaptation to environmental stress (Decarlo et al., 2017). ...
... As sessile estuarian filter feeders, mussels are well-established as sentinel organisms for biomonitoring environmental contamination (Goldberg, 1986). Specifically, G. demissa is well documented as a keystone bio-indicator species for the assessment of water quality (Bergen et al., 2001;Galimany et al., 2014;Giarratano et al., 2014;Halem et al., 2014). G. demissa reside in a wide range of geographical environments, from the Gulf of Lawrence, Canada to Florida, in mostly intertidal habitats, and experience a broad spectrum of salinities. ...
... p=0.0063 for pH values. Revised from Halem et al. (2014). A. Ravaschiere et al. ...
Article
Full-text available
Waterways in urban areas often act as repositories for sewage, industrial waste, and environmental contaminants. In response, inhabitants of these watersheds undergo physiological adaptations specific to their respective environments. Effects of these stressors can be assayed by quantification of various well-documented biomarkers in sentinel species such as the Atlantic Ribbed mussel, Geukensia demissa, a native to the Bronx River Estuary, Bronx, NY, USA. Heat shock protein 70 (Hsp70) is a universally expressed biomarker for an array of environmental stressors including toxins and low dissolved oxygen. To better understand the mechanisms by which organisms tolerate their contaminated environments, we monitored the constitutive and heat shock-induced levels of two proteins: Hsp70 and acetylcholinesterase (AChE) in natural populations of G. demissa from differentially impacted sites: the Bronx River and Greenwich Cove estuaries. We show that G. demissa from the Bronx River exhibits a higher level of constitutive Hsp70, and launches a more rapid and robust heat shock response than does its Greenwich Cove counterpart. In addition, AChE levels are recovered more quickly in Bronx River mussels. Based on response pattern investigations from heat stress as well as constitutive expression, we suggest that the Hsp70/AChE chaperone/client relationship exemplifies the unique adaptive mechanisms utilized by organisms in order to tolerate environmentally impacted habitats. Results from this study offer important insights from an ecological perspective into the molecular and cellular basis of stress response and provide valuable information regarding adaptation to the increased demands of challenging environments.
... In our study, this could explain the greater stress sensitivity of male as compared to females that were not significantly affected by co-exposure of hypoxia and acidification. In fish studies, abundant evidence showed that hypoxia is related to endocrine disruption (Landry et al., 2007;Friesen et al., 2012;Halem et al., 2014). Hypoxia could mediate inhibition of cytochrome P450 aromatase (an enzyme responsible for estrogens biosynthesis) activity (Halem et al., 2014), such mechanism may impact the sexual differentiation of fish (Landry et al., 2007), but further research is needed for mussels. ...
... In fish studies, abundant evidence showed that hypoxia is related to endocrine disruption (Landry et al., 2007;Friesen et al., 2012;Halem et al., 2014). Hypoxia could mediate inhibition of cytochrome P450 aromatase (an enzyme responsible for estrogens biosynthesis) activity (Halem et al., 2014), such mechanism may impact the sexual differentiation of fish (Landry et al., 2007), but further research is needed for mussels. ...
Article
Ocean acidification and hypoxia have become increasingly severe in coastal areas, and their co-occurrence poses emerging threats to coastal ecosystems. Here, we investigated the combined effects of ocean acidification and hypoxia on the reproductive capacity of the thick-shelled mussel Mytilus coruscus. Our results demonstrated low pH but not low oxygen induced decreased gonadosomatic index (GSI) in mussels. Male mussels had a lower level of sex steroids (estradiol, testosterone, and progesterone) when kept at low pH. Expression of genes related to reproduction were also impacted by low pH with a downregulation of genes involved in gonad development in males (β-catenin and Wnt-7b involved in males) and an upregulation of testosterone synthesis inhibition-related gene (Wnt-4) in females. Overall, our results suggest that ocean acidification has an impact on the gonadal development through an alternation of gene expression and level of steroids while hypoxia had no significant effect.
... Micropoluentes são frequentemente encontrados em água doce e em sistemas marinhos ou estuários, oriundos de várias fontes (Nödler et al., 2014). Historicamente, os corpos hídricos sempre foram utilizados como receptores de diversos poluentes (Halem et al., 2014;Maciel, et al., 2015;Köck-Schulmyer et al., 2019;Petrie et al., 2019). Atualmente a preocupação com a qualidade das águas tem aumentado no cenário mundial. ...
Book
Full-text available
Baia de Guanabara
... Micropoluentes são frequentemente encontrados em água doce e em sistemas marinhos ou estuários, oriundos de várias fontes (Nödler et al., 2014). Historicamente, os corpos hídricos sempre foram utilizados como receptores de diversos poluentes (Halem et al., 2014;Maciel, et al., 2015;Köck-Schulmyer et al., 2019;Petrie et al., 2019). Atualmente a preocupação com a qualidade das águas tem aumentado no cenário mundial. ...
... Micropoluentes são frequentemente encontrados em água doce e em sistemas marinhos ou estuários, oriundos de várias fontes (Nödler et al., 2014). Historicamente, os corpos hídricos sempre foram utilizados como receptores de diversos poluentes (Halem et al., 2014;Maciel, et al., 2015;Köck-Schulmyer et al., 2019;Petrie et al., 2019). Atualmente a preocupação com a qualidade das águas tem aumentado no cenário mundial. ...
Chapter
Full-text available
Neste capítulo, abordamos (1) a diversidade de habitats de substrato consolidado da Baía de Guanabara, (2) os costões da baía, (3) os substratos duros naturais, (4) os substratos duros artificiais, (5) os substratos duros artificiais móveis, tais como cascos de navios e plataformas de petróleo, (6) os organismos típicos de substratos duros da baía, (7) as comunidades bentônicas como modelo ecológico e (8) os substratos não consolidados. É apresentada também uma tabela não exaustiva das espécies exóticas de substrato duro encontradas na Baía de Guanabara. Available: https://aequor.site/material-educativo/
... Thereby, the estuarine pollution is one of the most worrying [4], being highly affected by direct discharges and activities as well as by upstream contamination. Some of the emergent compounds are endocrine disruptor chemicals (EDCs), as they interfere with the normal functioning of the endocrine system of invertebrates and vertebrates (fish, birds and reptiles), causing abnormalities in the reproductive system of animals, intersex gonads, changes in the expression patterns of genes involved in the synthesis of sexual hormones and of vitellogenin, reduction in the quantity of sperm, decrease in outbreaks of eggs delayed metamorphosis as well as changes in growth and behavior [5][6][7][8][9][10][11]. In humans, these effects include a reduction in sperm count, increased incidence of breast, testicular, prostate cancer and endometriosis [12]. ...
... These compounds can cause alterations in the endocrine system of several organisms, including mussels, fishes, birds, reptiles, and mammals, and may lead to reproductive disturbances like imposex, hermaphroditism, masculinization and feminization, as well as disturbances in sexual relationships and population declines (Janex-Habibi et al., 2009;Verbinnen et al., 2010). Substances presenting estrogenic activity can have long lasting effects in human reproductive system, even if this exposure occurred in utero (Halem et al., 2014;OECD, 2012;Rocha et al., 2014). ...
Article
Endocrine disrupting compounds (EDCs) can be found in domestic sewage, wastewater treatment plant effluents, natural water, rivers, lakes and in the marine environment. Jurujuba Sound, located in the state of Rio de Janeiro, Southeastern Brazil, receives untreated sewage into its waters, one the main sources of aquatic contamination in this area. In this context, the aim of the present study was to evaluate the estrogenic potential of water sampled from different depths and from areas with differential contamination levels throughout Jurujuba Sound. Water quality was evaluated and acute toxicity assays using Allviibrio fischeri were conducted, while estrogenic activity of the water samples was determined by a Yeast Estrogen Screening assay (YES). Water quality was mostly within the limits established for marine waters by the Brazilian legislation, with only DOC and ammoniacal nitrogen levels above the maximum permissible limits. No acute toxicity effects were observed in the Allivibrio fisheri assay. The YES assay detected moderate estrogenic activity in bottom water samples from 3 sampling stations, ranging from 0.5 to 3.2ngL-1, as well as in one surface water sample. Estrogenic activity was most frequently observed in samples from the bottom of the water column, indicating adsorption of estrogenic compounds to the sediment.
... However, there are always several issues that alter the balance of coastal dynamics, causing environmental impacts, largely motivated by conflicts of interest among uses such as recreation, port activity, and mining (Johnson-Restrepo et al., 2008;Gavio et al., 2010). Human impacts on nature, combined with natural processes, have triggered a largely ignored emergent phenomenon on organisms, such as changes in reproductive function derived from exposure to endocrine disruptors (Petro et al., 2012;Giusti and Joaquim-Justo, 2013;Halem et al., 2014). These studies point to the need for further research to determine the extent of which the human population may be affected. ...
Article
Full-text available
Imposex is the development of male sexual characteristics caused by the toxic effects of some chemicals that acts as an endocrinal disruptor. Antifouling paints contain these chemicals. Cartagena lacks studies to indicate the extent of imposex in its coastal waters. The aim of this study was to determine the prevalence of imposex in the gastropod Stramonita haemastoma in Cartagena, Colombia. Specimens were collected during 2013 from locations of high and low influence of port activity. Morphometric measurements and the frequency of the occurrence of imposex were registered. The comparison among morphometric variables showed statistically significant differences between the two sites studied. Furthermore, the females of the S. haemastoma species presented an imposex frequency of 93.1% in Birds’ Island, Cartagena Bay, compared to 31.8% in La Bocana. The relative penis size index or RPLI (10.145 and 3.231) and vas deferens sequence index or VDSI (2.83 and 1.16), showed possible contamination by organotin compounds in both places.
Article
Organisms living in temperate and polar regions experience extensive seasonal changes in the physical and biotic environment, including temperature, insolation, and food availability, among other factors. Sessile intertidal organisms respond to such seasonal fluctuations largely through physiological and biochemical means, because their behavioral responses are severely limited. In this study, we used a proteomic approach to examine changes in seasonal protein expression of gill from the intertidal mussel Geukensia demissa, a keystone species of the western Atlantic salt marsh, over the course of one year. Gill tissue of mussels collected in summer had the greatest number of proteins significantly increased in abundance (37 of 592 spots detected on two-dimensional polyacrylamide gels), although autumn mussels revealed a comparable proportion of up-regulated proteins (31 spots). In contrast, the number of proteins changing in abundance in winter and spring mussels were substantially smaller (15 and 9, respectively). Identification of these proteins revealed both expected and unanticipated changes to the proteome. Maintenance of gill cilia dominates in the summer when filter-feeding is most active, as evidenced by cytoskeletal proteins such as tektin-4 and tubulin isoforms; a signal of protection from heat stress is also present in summer (e.g., heat shock cognate 70). In autumn oxidative stress protection (peroxiredoxin-5 and manganese-containing superoxide dismutase) and aerobic ATP synthetic capacity (ATP synthase subunits a and delta) appear to increase. In winter a signal of cold-induced oxidative stress is apparent (Mn-SOD and NADP-dependent isocitrate dehydrogenase), perhaps in association with heavy metal toxicity and exposure to pathogens. Gill tissue from spring shows relatively little environmental acclimatization, other than a possible increase in protein synthesis capacity.
Article
Full-text available
Although much biological research depends upon species diagnoses, taxonomic expertise is collapsing. We are convinced that the sole prospect for a sustainable identification capability lies in the construction of systems that employ DNA sequences as taxon 'barcodes'. We establish that the mitochondrial gene cytochrome c oxidase I (COI) can serve as the core of a global bioidentification system for animals. First, we demonstrate that COI profiles, derived from the low-density sampling of higher taxonomic categories, ordinarily assign newly analysed taxa to the appropriate phylum or order. Second, we demonstrate that species-level assignments can be obtained by creating comprehensive COI profiles. A model COI profile, based upon the analysis of a single individual from each of 200 closely allied species of lepidopterans, was 100% successful in correctly identifying subsequent specimens. When fully developed, a COI identification system will provide a reliable, cost-effective and accessible solution to the current problem of species identification. Its assembly will also generate important new insights into the diversification of life and the rules of molecular evolution.
Article
Full-text available
Results from reaeration experiments are presented for three cases: case 1: reaeration by bottom generated turbulence for open channels; case 2: reaeration by surface generated turbulence due to wind on water, and case 3: reaeration by wind on channel flow, in which effects of bottom generated turbulence and of surface generated turbulence are combined. The main results are curves showing the reaeration factor kL as function of σu, the rms value of the horizontal component of the velocity near the surface. Correlations are found for each of the cases, with scattering about average curves which might be purely random. However, large differences exist in the trends for the different cases. In order to generalize the results, and to apply them to cases where no data exist, an attempt is made to correlate σu with parameters of the mean flow, by means of a dissipation velocity uε calculated from the average dissipation. Good results are obtained for cases 1 and 2, and can be extended to correlate the data for case 3.
Chapter
Full-text available
GOMES, R.L. AND LESTER, J.N., 2003. Endocrine disrupters in receiving waters. In: BIRKETT, J.W. AND LESTER, J.N., ed., Endocrine Disrupters in Wastewater and Sludge Treatment Processes CRC Press, Boca Raton, Florida. 177-218
Article
The equations of Streeter and Phelps for the BOD and dissolved-oxygen profiles along a natural stream are extended to take into account the effects of longitudinal dispersion, removal of BOD by sedimentation, addition of BOD along the path of flow, removal of oxygen by plant respiration and by the oxygen demand of benthal deposits, and the addition of oxygen by photosynthesis. Methods by which various coefficients in the equations might be evaluated from theory or from field measurements are examined. The effect of longitudinal dispersion on the BOD and dissolved-oxygen profiles is shown to be negligible in most fresh water streams. A theory of reaeration, based on the random replacement of the interfacial liquid-film, is presented. It is proposed that the micro-scale portion of the turbulent energy spectrum principally is responsible for the film replacement on which reaeration depends. Theoretical values of the reaeration coefficient are in good agreement with values reported in the literature.
Chapter
Urbanization changes fluvial systems more drastically than any other single human activity. This chapter outlines approaches to the study of urbanization in river channels, the nature of the urbanization process, alterations of the surface land cover, changes in hydrologic and sediment regimes, and resulting responses in channel morphology and in aquatic and riparian systems. Morphological adjustments can produce urban channels up to 15 times larger than their natural counterparts. Implications for river management relate to sophistication levels of urban stormwater management. Opportunities for fluvial geomorphology involving a holistic approach, with restoration where feasible, are compatible with a sustainable urban future.
Article
Species boundaries of some Mactridae species are difficult to define by morphology due to phenotypic plasticity and morphological convergence. DNA barcoding might provide an effective resolution for the confusion. Here, partial sequences of mitochondrial cytochrome c oxidase subunit I (COI) and 16S rRNA genes from 36 specimens of 11 species are sequenced to assess whether Mactridae species could be distinguished by DNA barcoding techniques. An evident barcoding gap was detected in the COI analyses, while barcoding gap for 16S was not found. Nevertheless, neighbour-joining and Bayesian trees showed that all species but one (Coelomactra antiquata) fell into reciprocally monophyletic clades with high bootstrap support. Results of sequence divergence and topology in Bayesian inference of phylogenetic tree suggested the occurrence of potential cryptic or sibling species in the C. antiquata group. This study demonstrates the efficacy of species identification in Mactridae species via DNA barcoding.
Article
Temporal and spatial (depth) patterns of shell growth were studied in the mussel Mytilus edulis in relation to water temperature and potential food availability, at an offshore oil platform, Holly (ARCO), in the Santa Barbara Channel, California. Length-specific growth rates were highest from late May to July and at a depth of 9 m. The time to achieve a length of 50 mm from recruitment was estimated at 6–8 months. Growth rates were not correlated with water temperature, using multiple regression and correlation analysis. Temporal variation in the growth of 20- and 35-mm mussels correlated with chlorophyll a concentration at time lags of 2 and 4 wk, respectively. Variation in growth of mussels with depth was more closely associated with the concentration of particulate organic carbon than with chlorophyll a. Our results indicate that water temperature can be disregarded as an important factor in regulating mussel growth in California waters, but that growth could vary in association with well-documented regional variation in phytoplankton biomass.