Fish Flashcards
(41 cards)
Microplastic particles can be transported from
freshwater to marine habitats
and have been detected in more than 100 fish species around the
world
Laboratory studies have revealed
the negative
impact of microplastics in fish; such as intestinal damage and
inflammation from short to long term exposure
microplastics can enter
internal organs after adhering to the gills
and skin
There is widespread recognition that wetlands provide
valuable ecological services including habitat for species, protection against
floods, water purification, amenities and recreational opportunities
The sex of adult in-
dividuals can be easily distinguished on the basis of externally
visible characteristics (Leusch et al., 2006), which allows for
gender-dependent investigations in pollution monitoring.
on the basis of externally visible characteristics (Leusch et al., 2006), which allows for
gender-dependent investigations in pollution monitoring
some urban wetlands are specifically
designed to treat
urban runoff and to receive stormwater which
makes them more vulnerable to environmental stress via anthro-
pogenic influence and contamination
we know that microplastics can
occur
in natural wetland sediments, waters and birds However, monitoring of plastic levels in urban wet-
lands and their inherent taxa is uncommon. Urban wetlands receive
a considerable amount of material carried by surface run-off, and
therefore constitute an important source of microplastic pollution
In addition, urban wetlands are typically
small water bodies that are heavily influenced by surrounding
catchment land use. The seriousness of microplastic pollution in
small water bodies has been highlighted in some regional case studies
Gambusia holbrooki (Eastern mosquitofish) is invasive in
mostcontinents under a wide range of temperate climate conditions.
Because of its widespread distribution, high abundance, ease of
capture and ability to adapt to laboratory settings, Gambusia hol-
brooki is a common model fish for ecotoxicological testing and
environmental monitoring
The accumulation of metals and persistent organic pollutants has been observed in Gambusia holbrooki
while few studies have investgated microplastic accumulation
Facts about Gambusia holbrooki
- an invasive species in Austrlia
- has ahigh level of biomass and dominance in some wetlands and small
water bodies - are a hardy species and are often found inhabiting polluted artificial
ponds and wetlands where native species do not occur - biomonitoring and routine investigations
based on Gambusia holbrooki has limited impact on understanding
pollutant effects on local, native fish populations, but does provide
valuable information regarding impacts on resident species within
polluted ponds and wetlands. - Given that microplastic research is substantially lacking for
freshwater biota in the Southern Hemisphere, we conducted an
investigation to determine the baseline pollution level of micro-
plastics in Gambusia holbrooki. Fish size, weight and gender
The greater Melbourne metropolitan area supports a population
of
approximately 4.5 million and encompasses a catchment area of
approximately 12,800 km2 ,
It contains a complex network of rivers, streams and constructed wetland sys-
tems.
These wetlands are constructed for the interception and
treatment of stormwater, to attenuate flows during storms and to
treat water quality.
Recording the colour was not considered necessary because
The digestion process can discolour the particles. Based on their
morphology, microplastics were classified into four shapes: fiber,
film, fragment or pellet
The specific polymer composition was identified under
All spectra were compared
with a database from Bruker for verification. Spectra matching with
a quality index more than 70% were accepted and the abundance of
microplastics was re-calculated by removing all the verified non-
plastics. Of all 194 visually identified items, 109 items were veri-
fied. Such a validation rate (57.6%) was higher than the generally
accepted level (50%)
the attenuated total reflec-
tion (ATR) mode of a micro-Fourier Transform Infrared
Spectroscopy (m-FT-IR, Bruker, LUMOS)
All spectra were compared
- with a database from Bruker for verification.
- Spectra matching with
a quality index more than 70% were accepted and the abundance of microplastics was re-calculated by removing all the verified non-plastics. - Of all 194 visually identified items, 109 items were verified. Such a validation rate (57.6%) was higher than the generally accepted level (50%)
To evaluate any background contamination we set up
one blank control for every three samples, totaling 120 blanks.
For each blank fish tissues were replaced
- by 2 ml filtered water and analyzed
simultaneously with other samples. - Eight items were confirmed in
blanks which equated to 0.067 items/ind., 0.033 items/g and a
detection rate of 6.67%. - We have corrected all our results by sub-
tracting the mean level of background contamination from those
blanks to account for this error.
Polymer identification in fish body and head:
Of the 109 selected items from fish bodies and heads
- 68 items were confirmed as plastic (62.4%).
- Eleven polymer types were identified: the most common polymers were polyester (25.7%),
rayon (10.1%),
polyamide (7.3%) and polypropylene (5.5%) (Sup-
plementary tables Table S4). - In particular, polyester and rayon
occurred in more than 70% of sampling sites. - Sixty plastic items (72.3%) belonging to 11 polymer types were
identified from body samples - 8 plastic items (30.8%) belonging
to 5 polymer types were identified from head samples (Fig. 2A andB). - Polyester and rayon were frequently detected in fish bodies
across all sampling sites while polyester and polyamide were more commonly detected in fish heads - (mean = 7.2%) of fish showed microplastics in the head (Table 1).
The average abundance of microplastics in bodies ranged
- from 0.18 items/ind. to 1.13 items/ind. (0.52 items/g to 4.4 items/g)
- with a mean level of 0.60 items/ind. (1.94 items/g).
- In heads across sites,the average detection rate ranged from 0 items/ind. to 0.28 items/ind. (0 items/g to 12.5 items/g) with a mean of 0.11 items/ind. (3.1
items/g) (Table 1).
The abundance of microplastics
in bodies was
significantly higher than those in heads in terms of
items/ind. (p < 0.05).
Fiber was the most common morphology observed in both the
bodies and heads of the fish, comprising 62.5%e100% of micro-
plastics found at each wetland except those from S5 where no
microplastics were identified (p < 0.05) (Fig.
Characteristics of microplastics in different parts of fish:
The microplastic sizes ranged from
- 0.09 mm to 4.86 mm in bodies an
- 0.22e2.01 mm in heads.
- Microplastics of a size less than 1 mm were
prevalent, accounting for 52.9% of microplastics found in fish
bodies and 83.9% in fish heads (Supplementary materials Fig. S1). - The microplastics found in the bodies were significantly larger than those found in the heads
- head parts were significantly greater than fish without
microplastics in the body (p < 0.01)
Female individuals contained more
- microplastics in their bodies
than males (p < 0.05) (Fig. 5 A) - but not in their heads (p > 0.05)
(Fig. 5 B). - Regarding microplastic shapes, female fish contained
more non-fibers in their bodies than males.
microplastic pollution levels in an Australian freshwater fish from the Greater Melbourne Area.
- investigations into the microplastic pollution in
freshwater organisms are few compared to similar studies of ma-
rine organisms. - in addition, this is the first known field study to
specifically target microplastics in Gambusia holbrooki. - Based on the available literature, the average abundance of microplastics in freshwater fish, amphibians and invertebrates can range from 0.5 items/ind. to 19.2 items/ind. (Table 2).
- More than 70% of those studies had microplastic detection rates which exceeded 20%.
- In comparison, of the 19.4% of fish found with microplastics in this
study, there was an average abundance less than 1 items/ind. * *Our results indicate a relatively low prevalence of microplastic pollution in Gambusia holbrooki from the Greater Melbourne Area compared to similar studies completed elsewhere on other species
