Download effect of beach grooming

Chi Chang
Marine Ecology 529
Dr. Steele
March 19, 2015
Impacts of Beach Grooming on Marine Biodiversity
Abstract.
The role of beach grooming were investigated in terms of its effect on the loss in abundance of
invertebrate and species diversity. In the current study the presence and absence of 15 species
that inhabit sandy beaches in southern California was assessed at 2 sites, Zuma which are
groomed and el matador the un-groomed beach, species richness was found to be 3 times lower
compared to un-groomed. The statistical analysis were utilize to determine significance in
concerning difference in the densities of all invertebrate species, density of each species and
number of species per transect between the two beaches are all determined to be p<0.001, which
conclude in significant data in supporting the evidence of declining in species diversity of marine
dweller on sandy beaches reflects upon beach grooming rather than sampling error or chance. In
conclusion consistent beach grooming prominently reduce the biodiversity and biomass found on
sandy beaches. Because of the negative effect beach grooming have, the increasing and
expansion of beach grooming on further more beach is going to be a problem gradually driving
species extinct a larger efforts required in conservation of sandy beach ecosystem.
Introduction
The world’s coastline are dominated by sandy shores (McLachlan and Brown, 2006), As a result
of the countless sandy beaches beachgoers, beach grooming is done in many beaches in the
world and some research have already accomplish stating many sandy beach ecosystems have
now been lost (Nordstrom, 2000) and many more are increasingly suffering from the negative
impacts of a range of anthropogenic activities such as beach grooming.
Beach grooming is the upheld process of removing debris and seaweed from the beach by
tractors pulling rakes in favors to beachgoers disgust toward flies along the kelp wrack, beach
hoppers, etc. In order to see the effects of beach grooming we conducted investigation on the two
beach, the groomed beach Zuma and un-groomed beach El matador.
Ocean sandy Beach environments involves unsteady factors of sand, wave climates the wind,
and tidal regime (McLachlan and Dorvlo, 2005) therefore only organisms able to withstand that
are able to inhabited on Sandy beaches, the distinctive groups of marine organisms are often
scattered in terms of its settlement on the beach. Macrofauna or macrobenthos are the term used
to describe larger invertebrates that live and feed on or in sediment. Many of the sandy beach
organism found are Macrofauna or Infauna.
Kelps wracks are a major source of food and shelter to various sandy beach habitants due to its
containment of moisture, it is great place for organism to rest from heat and desiccation. Kelp
wracks are kelps that got washed up by waves and tides. In most beaches Algae and surfgrass
mainly of the macroalga species macrocystis pyrifera gathered on top of the sand. Food chain
occur beginning with the alga and primary consumer kelp flies Fucellia costalis and beach
hoppers (amphipods in the genus Megalorchestia) which is then eaten by secondary consumer
rove beetles or bird. So the presence of kelp wrack are very essential relative to maintaining a
sandy beach ecosystem.
The purpose of conducting this study is to determine if beach grooming affects the biodiversity
of sandy beach invertebrates by comparing species richness, the density of all species combined
and density of each species between groomed and ungroomed beach
Materials and methods
The study area was conducted on the two beaches in south California, the ungroomed beach El
matador on February 26, 2015 and the groomed beach Zuma on March 5, 2015. Same method of
sampling was applied to both beaches. Sampling begin by first laying out transect along the
beach that run perpendicular to the water’s edge and extend through a number of different
environmental parameters. For every 2 meters of the transect beginning at 0, a shovel is used to
dig up as much sand as it can hold as one sample. The sand and the organisms within the sand is
then transferred onto a mesh square which will be wrapped together by the mesh and then wash
out the sands in the ocean. Each sample of Organisms in the mesh is then identified, quantified
and recorded on to data sheet. Presence of kelp wrack is also recorded in each samples. Transects
are done 2m inland and away from water’s edge. 21 transects was done on each of the beach El
matador and Zuma.
The a statistical analysis and graphic software SYSTAT was used to conduct Mann-Whitney U
test in order to obtain significant difference in the densities of all invertebrate species, density of
each species and number of species per transect between the two beaches.
Results:
Species richness revealed total of 15 species present in the ungroomed beach and 5 species in
groomed beach zuma.
the means of number of
species per transect
comparison
4.5
number of species
4
3.5
3
2.5
2
1.5
1
0.5
0
E.M(Ungroomed) Zuma(Groomed)
Figure 1. Display the mean differences in numbers of species per transects between ungroomed
beach el matador and groomed beach Zuma.
density of all invertebrate species
comparison
species density
1.5
1
0.5
0
E.M(Ungroomed)
Zuma(Groomed)
Figure 2. The mean in the density of all invertebrate species combined shown between
ungroomed beach el matador is two times the density of groomed beach Zuma.
significant
number difference
of
in the
species densities of
per
all
transect invertebrate
species
pP
P <0.001
value
<0.001
df
1
1
Table 1. p-value gathered from Mann-Whitney U test from the comparison between the two
beaches of densities of all invertebrate species and number of species per transect all test out to
be P<0.001 which is below the significance level. Degree of freedom is 1 for both comparison.
Density of each invertebrate species comparison
0.8
0.7
0.6
species Density
0.5
0.4
0.3
0.2
0.1
0
-0.1
El.Matador(Ungroomed)
Zuma(Groomed)
Figure 3. The variances in density of each species is displayed between un-groomed beach el
matador and groomed beach Zuma.
U-test
beach hopper (Megalorchestia spp.)
p-value
P
<0.001
P
<0.001
herbivorous isopod (Tylos punctatus)
carnivorous isopod
(Cirolana&Excirolana)
.195
bloodworm (Euzonus mucronata)
.090
predatory polychaete (Nephtys)
0.989
unidentied polychaete worm
0.317
sand crab (Emerita analoga)
0.15
other sand crab (Lepidopa californica)
0.317
unknown beetle larvae
0.317
unknown insect pupae
0.317
rove beetle (Thinopinus pictus)
0.317
red mite (Neomologus)
0.317
kelp fly (Coelopa sp.)
0.317
black beetle (unknown sp.)
0.317
pseudoscorpion
0.317
Table 2. P-value and density of each species between the two beaches is shown.
Discussion.
The means of the number of species per transect from Figure.1 of the groomed beach are shown
to be a twice the loss in species richness compared to of un-groomed beach El. Matador. In
Figure.2 the comparison of density combined is also a two times relationship amongst the two
beach, both figures are clear evidence in showing the result of beach grooming on density of
invertebrate and its diversity.
According to Table 1. Densities of all invertebrate species and number of species per transect
was determine to be p<0.001 which is below the significance level so both data of densities
combined and number of species per transect are statistically significant, meaning the
relationship between beach grooming and decline in sandy beach organism’s abundance and
diversity is something other than mere random chance. This finding is great evidence in
supporting the negative impact of beach grooming.
The reason more than half species’ density of each species from at table. 2 are not statistically
significance is mostly due to the small amount of sample size collected in this studies, and more
difficulty in finding rare species of organisms. one species in particular the predatory polychaete
(Nephtys) result in no change in the abundance between the two beaches, this shows not all
invertebrates are equally affected by beach grooming, due to the possibilities of its food source
not being the kelp nor shelter gained from the kelp, another possible reason may also be due to
the insufficient duplication and sampling size being too small. Although the studies was done in
simply two locations and more research are required in order to develop the perfect causation
and extensiveness of the effect beach grooming may have. Our result does indicate
Significant negative impact of beach grooming on the abundance and species richness, and this is
happening throughout all the constant groomed beaches. Because of this more extensive
conservation are necessary starting from now in order to avoid possible swift drop of diversity in
the future.
References
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Marine Biological Association of the United Kingdom 70.03 (1990): 683.
Dugan, Jenifer, and David Hubbard. 2010. Loss of Coastal Strand Habitat in Southern
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Ecology-pubblicazioni Della Stazione Zoologica Di Napoli I. 15, no. 3-4: 177-211.
McLachlan, Anton, and Atsu Dorvlo. 2005. Global Patterns in Sandy Beach Macrobenthic
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Nordstrom, K.F. 2000. Beaches and Dunes on Developed Coasts. Cambridge University Press: