Cottesloe Ecosystem Research Project 2014

Influence of Abiotic Disturbances on

Benthic Producer Distribution in the

Cottesloe Fish Habitat Protected Area

Leanne Ward, Charlotte Ryan, Eric Hay, Henry Lambert,

Julian Keller, Anne Feng, Hanna Jabour, Sara Dreijer

2

Abstract

The impact of physical events such as winds, currents and wave energy play an important role

in the growth and establishment of benthic communities. The primary producers are sensitive

to these disturbances, and their resilience is limited if the harmful event is frequent and

intense. The benthic data were collected through a 0.25m2 quadrat in 3 habitat zones: the

lagoon, flat reef and broken reef, at the North side of Cottesloe Beach - a Fish Habitat

Protection Area. The investigated benthic genera were red algae, green algae, brown algae

and seagrass. Also, complementary benthic data from the last 3 years were gathered from

previous studies. The data presented here suggested that seagrasses occurred in lower energy

environments and are highly influenced by seasonal variation, while seaweed are more

resistant to higher energy events. Furthermore, gaps in seaweed and red algae were found to

link with high wave energy. Brown algae are benefitted by low-level disturbance due to an

inverse relationship with the seagrass development. The average abundance of seagrass from

2011 to 2013 decreased by 30%, however it increased 20% from 2013 to 2014. Brown algae

increased from 2011 to 2013 by 20%, however it decreased during the last year by 15%. Since

green algae were found in a minimal abundance, there is no significant trend to be established

about red algae and green algae. Further observations are required to fully understand the

relationship between population sizes of primary producers in the Cottesloe Reef Ecosystem,

and the increasing intensity of physical disturbance.

Introduction

Abiotic disturbances such as storms and irregular weather patterns have the capacity to

drastically affect not only terrestrial environments, but marine systems also. Not all species

respond to these extreme weather events in a uniform manner however, and some organisms

are affected more than others.

The impacts of wind forcing, waves and currents are widely understood and strongly linked to

the removal of benthic primary producers from established habitats due to physical

disturbance and associated sediment nutrient disturbance (Kendrick et al. 1998). The intensity

and level of the disturbance often dictates whether this event will benefit the benthic

community, or instead have a negative effect on its recovery processes (Wernberg et al. 2011).

Severe storm and wind damage can have a devastating affect on the reef ecosystem, as it can

suppress or compromise the sea grass and microalgae’s ability to recover. This is enhanced if

the occurrences are becoming more frequent and intense, as the community will not have

enough time or resilience strength to recuperate or survive after consecutive episodes

(Wernberg et al. 2011).

3

Establishing direct links between species abundance and disturbance is theoretically viable,

however a large amount of other factors affect the growth and establishment of communities

of primary producers (Kendrick et al. 1998). These include nutrient availability in the water

column or sediment, disturbance of sediment by tides, waves or macrofauna, sediment

stabilisation by films of microalgae, the availability of light and the amount of meiofaunal

grazers (Davis & Lee 1983; Rasmussen et al. 1983; Wasmund 1984; Höpner & Wonneberger

1985; Sundbäck & Granéli 1988; Sundbäck & Jonsson 1988; Delgado et al. 1991; Sun et al.

1993). Therefore linking decreases in species abundance to high wind events is viable only

when all other factors are constant, and within the dynamic ocean it is highly unlikely that

wind is the only factor influencing the observed changes. Understanding the differences in

these types of benthic primary producers’ habitats and controlling factors is vital to proper

future conservation effort and for maintaining the health of the near-shore ecosystem which

relies heavily on well established, growing populations of seagrass and algae species to

support all trophic levels.

Over the recent years, the effects of anthropogenic climate change are becoming more

prevalent and we have seen considerable differences in temperature, precipitation and

consequential weather patterns (Houghton 2009). The variation, frequency and intensity of

severe weather events, such cyclones and storms, have been significantly noticed throughout

the world, including Australia (Hughes 2003). Unfortunately, research and information

reflecting the relationship between climate change and the increase in storm disturbance in

Western Australia is lacking. However projections and reports based on world data suggest

this link is to be expected now and in the future (IPPC 2001). Thus our experiment focuses on

the damaging effects from storm associated winds, to the Cottesloe Reef Ecosystem region,

and the implications on the differing species of primary producers that are protected in this

area (Wernberg & Goldberg; Jones & Phillips; IPCC; 2011;2001).

The Cottesloe Reef Ecosystem, located offshore Cottesloe Beach, was declared a Fish Habitat

Protection Area (FHPA) in 2001 due to its accessibility and popularity within the local and

tourist community, which consequently demonstrated its vulnerability to human impact

(CERP 2011). This flourishing and unique ecosystem has been progressively threatened by

anthropogenic affects, such as overfishing, wastewater discharge and damage from boats

(Department of Fisheries 2001). Destructive activities including spearfishing or commercial

4

fishing, jet-skiing and anchoring boats within the FHPA, were prohibited to promote the

preservation of the aquatic biodiversity (Department of Fisheries 2001).

Cottesloe Reef covers a diverse range of habitat areas, comprising of the sandy near shore

lagoon, limestone reef, sponge beds, and kelp and macro-algae gardens. This marine

environment supports a diverse range of fish, invertebrates, aquatic plants and other reef

occupants that make it an important and valuable ecosystem to protect (CERP 2011). The

Department of Fisheries rely on the involvement of organisations and the community to help

ensure this region is protected for future generations (Department of Fisheries 2001). Thus,

the students from the University of Western Australia play an important role in the collection

and analysis of data that as a result allows for a greater understanding of this unique aquatic

ecosystem.

From data collected at the Cottesloe site over the past (three) years, there emerged a trend of

resistance of algal species to disturbance as they vary little in abundance from year to year

and across study zones. The impact observed on seagrasses however was much more

pronounced, as only small patchy communities exist in the lagoon area. These seagrasses are

sensitive to disturbance such as that associated with strong wind and wave events during

storms and seasonal storm variability (Kendrick et al., 1998). Therefore communities of

benthic primary producers, in this case algae and seagrass, are expected to be impacted and

progress differently after seasonal disturbance events. We then postulate that as a function of

climate change and related increases in storm frequency, duration and intensity, that

seagrasses will be more adversely affected than algal communities. This is due to the ability

of algae to attach themselves to rocky structures which are stable, where seagrass only gains

purchase in relatively mobile sandy areas (Marbà et al., 1996).

Though conservation efforts essentially focus on protecting the species of the Cottesloe Reef

Ecosystem from human impacts, it is likely that local seagrass communities may be lost as a

result of storm events and natural seasonal variation if the severity of these events were to

increase into the future. This has widespread implications for the entire reef ecosystem as

seagrasses provide habitat, food and sediment control, which impacts all trophic levels

(Marbà et al., 1996; Kendrick et al., 1998). It is clear that a trend of worsening storms will

have drastic effects on seagrass communities hence elucidating the level to which they are

5

impacted is paramount to perfecting conservation and mitigation efforts, not only locally but

globally.

This study aimed to discover the relationship between population sizes of seagrasses and red,

green and brown algae in the Cottesloe Reef Ecosystem, and the increasing intensity of

storms in Australia as a result of climate change. We hypothesised that increased frequency of

storms, has significantly decreased seagrass cover over recent years compared to previous

years, and that a lesser impact will be observed upon algal species cover.

Methods

Study site

The experiment was conducted in the Cottesloe Fish Habitat Protection Area at the end of

March 2014. The University of Western Australia established experiment boundaries in 2008

when they began conducting the annual experiments. The university divided the region into

two areas (north and south) and four key habitat zones. In this study, due to rough weather

conditions on the day, both zones were shifted slightly southward. The four habitat zones are

the lagoon, flat reef, broken reef and front reef, as can be seen in Figure 1. The front reef was

considered too deep and dangerous to study so only the first three zones were included in this

study.

6

Figure 1: North and south study area in the Cottesloe Fish Habitat Protection Area. Red zones show

habitat zones: (1) the Lagoon, (2) the Flat Reef, (3) the Broken Reef and (4) the Front Reef.

Primary producer sampling

We used a 0.25m2 quadrate that we placed down 6 times in each of the three zones. The

quadrate had weights attached to it so it would remain still on the bottom and a fluorescent tag

so it could be more easily spotted once released. Snorkeling gear was required to determine

the percentage cover of primary producers within the quadrate, as this was done through

visual estimation. There was an attempt to randomise the placement of the quadrate. However,

due to the weather conditions, it was difficult to estimate to what degree the quadrate samples

where spread out across the habitat zone.

The species coverage within the quadrate was recorded using a self-made laminated

identification chart, which was printed on waterproof paper. If a species was unidentifiable

either due to poor visibility or because it was not present on the chart, a photo was taken of it

so it could be identified later. The percentage coverage was decided using a standardised

coverage guide, as seen in Figure 2. The depth and total coverage was also recorded at every

quadrate sample site. The identification chart and the percentage coverage guide were

attached to a clipboard to prevent them from floating away during the in-water field study.

7

Figure 2: Percentage coverage chart (modified from Terry and Chilingar 1955)

Data analysis

The data collected in this study was entered into an Excel spreadsheet and shared in the

Cottesloe data file online, which allowed sharing of data between groups, and analysis of

previous years collected data. The recorded data was then analysed using pivot tables and

calculations were done based on the recorded average percentage coverage of groups of

macroalgae and seagrass species. The four groups looked at in this study, determined by

genus, were brown algae, green algae, red algae and seagrass. Each group was compared to

data over a four-year period, from 2011 to 2014, and plotted in relation to what year the data

was collected, to determine any changes in overall coverage over this period of time.

The average coverage data collected in this study, and studies conducted in previous years,

were assumed to be an accurate representation of the percentage coverage of primary

producers at the time of data collection. However, in reality, the visual estimations conducted

leave a larger margin of error and may have been affected by human error due to rough

weather conditions and low visibility in the water. Furthermore, this study assume that despite

the slight shift of the study areas towards the south the data still reflect an accurate

representation of the general area and is comparable to previous years.

Results

8

The following results from class data averages are presented in Table 1. The species were

grouped into four main categories based upon the genus they fall in: seagrass, brown algae,

green algae and red algae. The data was only taken from averages from the north side of

Cottesloe Marine Protected area due to the fact the majority of the data obtained for 2014

were from this area.

Table 1: The average % cover of each genus (seagrass, brown algae, green algae and red algae) and

the various zones they occur in (lagoon, flat reef and broken reef). The averages were taken from

quadrate averages and from class averages obtained.

Average Percentage Coverage

Red algae Green algae Brown algae Seagrass

Broken

Reef

12.931 0.690 34.897 0.000

Flat Reef 10.069 0.345 25.690 18.966

Lagoon 0.241 0.000 3.793 56.793

Mean 7.747 0.345 21.460 25.253

The reason for keeping data separate to the areas in which they occur in is due to the fact that

reef structure is different for each zone based upon different depths, and wave energy,

independent variables we want to control. The data is represented visually in Figure 3.

Figure 3: Data representing the average % cover of the seafloor for each category of primary producer

(red algae, green algae, brown algae and seagrass) in each of the various zones (broken reef, flat reef

and lagoon).

From the data it is readily able to distinguish that seagrass cover was highest in the lagoon

zone, and still present in the middle zone, the flat reef. Red and brown algae were more

prevalent in the two further zones (flat reef and broken reef) however there was not a

0.000

10.000

20.000

30.000

40.000

50.000

60.000

Broken Reef Flat Reef Lagoon

Av

era

ge

% C

ov

era

ge

Various Zones

Average of Red algae

Average of Green algae

Average of Brown algae

Average of Seagrass

9

significant difference in abundance in the two further zones. Green algae also followed the

same pattern as the other two species. However green algae was only found in a very minimal

abundance therefore it was difficult to make conclusions based upon this group. Overall,

based on this data, it was conclusive that seagrasses occurred in lower energy environments in

the lagoon areas, and algae were more prevalent in the higher energy further out zones.

When comparing the differences that have occurred over the last three years the data was

compiled together and then presented graphically in Figures 4, 5, and 6 for seagrass, brown

algae and red algae.

Figure 4: The abundance (%) of seagrass at Cottesloe Marine Protected area over the given time

frame of measurement 2011-2014. The three zones measured were not distinguished as we were

focusing on an overall shift over the last 4 years.

Based on Figure 4, it is evident that there was a significant decrease in abundance from the

2011 to 2012 period in which a decrease to the extent of 30% was observed. Additionally

after this year there was a trend in the increase in abundance in which there was an increase

from 5% to 25% cover of seagrass in 2014.

0.000

5.000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

2011 2012 2013 2014

% A

bu

nd

an

ce

Years

10

Figure 5: The abundance (%) of Brown algae at Cottesloe Marine Protected area over the timeframe

of 2011- 2014.

Based on Figure 5, there was a somewhat trend to the change in abundance of brown algae

over the last few years, in which a trend from 2011 to 2013 of increased abundance from

~12% to ~35% occurred. However from 2014 it was evident that a significant decrease of

15% in abundance had occurred from the values in 2013.

Figure 6: The abundance (%) of Red algae at Cottesloe Marine Protected area over the timeframe of

2011- 2014.

0

5

10

15

20

25

30

35

40

45

2011 2012 2013 2014

% A

bu

nd

an

ce

Years

0

1

2

3

4

5

6

7

8

9

10

2011 2012 2013 2014

% A

bu

nd

an

ce

Years

11

Based upon the results of the coverage of red algae, there was no significant trend to be

established. Furthermore the data taken from the 2012 year were only from one group, which

surveyed the north region in which they did not observe any red algae.

Discussion

In the analysis of our data we found a similar trend between the percentage abundance of sea

grass and of red algae species. Sea grass numbers drop from 34.78% cover in 2011 to 5.278%

in 2012, and begin to rise in the following years. Additionally, red algae follows a similar

trend by falling dramatically between the first two years, and then commences to rise in 2013

and 2014. The Bureau of Meteorology’s annual statement for 2011 revealed damaging storms

to be a feature of the year, with extreme gusts of winds recorded up to 126km/hr, in the Perth

vicinity (Bureau of Meteorology 2011). Additionally, the data collated by the National

Oceanic and Atmospheric Administration shows the wind vector magnitudes, during March

and April, over the past four years (Figure 7), and reflects the significant change in force in

2011 and 2014, compared to the other years (NOAA 2014). This demonstrates that these

weather disturbances could be directly linked with the trend seen by both the sea grass and red

algae species, and could explain the significant decline in species abundance in 2012. On the

other hand, the brown algae species did not follow this trend, as there was a gradual increase

in percentage abundance over the first three years, and a decline in 2014. Unfortunately green

algae data was insufficient therefore we could only make judgments based on the other three

groups. Our hypothesis suggested that we would see a decline in sea grass abundance and no

change in microalgae cover, over the years, but as shown by our data this is not the case,

therefore rejecting our hypothesis.

12

Figure 7: Each diagram, produced by NCEP/NCAR Reanalysis, shows the surface vector wind (m/s)

composite mean, from the years 2011 to 2014; focusing on the south west coastal region of Western

Australia (NOAA 2014). There is a difference in scale and colour coding between each individual map.

Due to the Cottesloe reef ecosystem being declared a FHPA, non-climate stressors such as

pollution, overfishing and boat disturbance are not an issue and thus the benthic assemblages

are reasonably strong, compared to various other locations that may be under the same

climatic stress but are not protected. Therefore, disturbance can play a vital role by changing

community structure for the better, as it can have important implications for local diversity,

productivity and species richness (Wernberg et al. 2011). The increased wave energy in 2011,

correlates with larger gaps in the sea weed and red algae cover in 2012, as this disturbance

ripped a significant percentage away from the reef. This fragmentation could have prevented

the dominant species from excluding others, and furthermore initiated succession (Harris et al

1984; Evans et al. 2012). This implication correlates with the rise in abundance over the

following years, as both types of seaweed were able to recover and then thrive with less

competition.

13

The trends in population shown above reflect the relative habitats of each species, as

abundance tends to drop with high wind events or disturbance in seagrasses and red algae.

However, species abundance is unaffected or positively affected by disturbance in brown

algae communities.

Seagrasses grow dominantly in sandy areas, most commonly in tidal lagoons near-shore,

preferring low energy environments and are highly influenced by seasonal variation (Marbà et

al. 1996). This is due to their root systems requiring a soft substrate to grow in typical of

lagoon environments (Marbà et al. 1996), and are therefore most easily disturbed and

removed during storm or high-wave events.

The brown algae, such as the species most commonly observed in our study Ecklonia radiata,

grows on rocky surfaces in medium to low energy environments such as lagoon boundaries,

fringing coastal reefs and deep rocky outcrops (Hatcher et al. 1987; Novaczek 1984). Brown

algae are in actuality benefitted by low-level disturbance as it provides room for juveniles of

the species to develop (Fletcher et al. 1983). This is why we observe almost an inverse

relationship of brown algae development to seagrass development, where seagrasses are being

removed, at the same time the same disturbance has allowed brown algae to grow where older

organisms have been removed.

Red algal species are more complex however, though a similar principle of seagrasses to red

algae applies. Red algae, or filamentous algae, are small, and delicate compared to its

Ecklonia r. counterpart. Red algae tends to grow on other algae or on the reef where there is a

gap in other species and is competitive for space on barren surfaces (Sousa 1979). The red

alga was also commonly observed at our study site near the branch or support of Ecklonia r.,

which provides some shelter from waves. Wave events associated with storms and high

intensity wind also have damaging effects to red algae, as it is relatively small and doesn't

have the same support as Ecklonia r. to the reef. It is easily removed and therefore similar

trends exist between seagrass and red algae development following disturbance events.

Intrinsic properties of each species determine their individual response to disturbance events

such as storms.

There are a variety of possible errors may have been caused via sampling and data

manipulation. Errors with sampling included the human error of over-judgement or under-

14

judgement of the actual percentage coverage, however this was minimized by the use of

percentage coverage comparison guides, though previous years may not have used the same

version. There may have been errors involved in identification of the species, as we had not

encountered the species before and were using photos and written descriptions as a guide. The

poor clarity of the water and lack of light penetration due to cloud cover would have also

contributed to this. We also did not use a method of randomising the placement of quadrates,

though manipulation of the data through deliberate placement of quadrates was unlikely,

because it was difficult to see where we were placing the quadrates due to the murkiness of

the water.

As for experimental design, because this study was done in-situ, it was impossible to control

other variables that may have an impact on seagrass and algae populations. Variables such as

temperature, acidity and sea level may all randomly vary with time, and have also been

impacted by the effects of climate change (Jones et al. 2004). Therefore, it was difficult to

determine the extent to which population change was due to storm activity.

Another cause for error in the results is the use of previous groups' data because they may

have not controlled variables the same way we did. In previous years, the methodology for

collecting data or the way they recorded the data may have been different. This may have

contributed to errors in the results. Also, there were species that we measured that were not

present in previous years, either due to their actual absence in the reef or because they were

not included on the previous groups' identification guides. For example, we differentiated

between asparagopsis and crustose red in the identification guide in this study, while

previous groups may have just grouped the two species together under the label 'filamentous

red algae'. However, this didn't have an effect on our results as we ended up grouping them as

red algae in the final graph outputs. In 2012, the red algae were not present at all, in which

may have been a sampling or recording error. Further investigation into this abnormal result

would be needed.

Also, because we only sampled the north Cottesloe area in this 2014 study, we only used data

from previous years that were of the north area so that variations in benthic composition

based upon differences in the north and south areas would not need to be considered. For this

reason it increased possible errors as we were extrapolating results from a smaller sampling

15

area. The amount of data we could use from previous years was also reduced because of this:

in 2013, we only used data from one group.

The main problem with the study is that the data only covered a brief time period. It was

difficult to determine a correlation between storms and seagrass and algae populations with

only four years of data, and with data only collected once a year. Therefore it is suggested that

more years of data collection, or more frequent data collection throughout a year, would be

required for a more accurate understanding of the relationship. Alternatively, a case study of

the Cottesloe Reef Ecosystem and its benthic producer populations after a significant storm

event could be considered. A case study would be especially effective in determining the

impact of storm activity because it would ensure that the storm would be the main cause of

any change in population as opposed to other variables.

Conclusion

In Summary we have indicated that it is difficult to state that there is some correlation with

storm activity and the benthic structure in the Cottesloe marine protected area over the time

fram of 2011- 2014. Overall an increased amount of data and studying of this region may

draw a clear link, however due to the short time frame it unlikely any long term trend will be

evident, without studies conducted over a longer time frame.

16

References

Bureau of Meteorology: Australian Government, 2011. Annual Australian Climate Statement

2011, Regular Statements. Accessed 22/4/2014 from:

http://www.bom.gov.au/climate/current/annual/aus/2011/

Dash, J, 2011, Extreme Weather and Climate Change: IPCC 2011 Report

Davis, M.W., Lee II, H., 1983. Recolonization of sediment-associated microalgae and effects

of estuarine infauna on microalgal production. Marine Ecology Progress Series, 11, 227–

232

Delgado, M., de Jong, V.N., Peletier, H., 1991. Experiments on resuspension of natural

microphytobenthos populations. Marine Biology 108, 321–328

Department of Fisheries, 2001. Plan of Management for the Cottesloe Reef Fish Habitat

Protection Area, Fisheries Management Paper No. 155, 9-17

Evans, B., Knox, B., Ladiges, P., Saint, R., 2012. Biology: An Australian Focus, McGraw-

Hill Australia Pty Limited, New South Wales, Australia, 558-570

Fletcher, W.J., Day, R.W., 1983. The distribution of epifauna on Ecklonia radiata and the

effect of disturbance. Journal of Experimental Marine Biology and Ecology, 71, 205-220

Harris, L., Ebelling, A., Laur, D., Rowley, R., 1984. Community recovery after storm

damage: a case of facilitation in primary succession, Journal of Science, 224, 1335-1337

Hatcher, B.G., Kirkman, H., Wood, W.F., 1987. Growth of the kelp Ecklonia radiata near the

northern limit of its range in Western Australia. Marine Biology, 95, 63-73.

Höpner, T.,Wonneberger, K., 1985. Examination of the connection between the patchiness of

benthic nutrient efflux and epibenthos patchiness on intertidal flats. Netherlands Journal of

Sea Research 19, 277–285

Houghton, J., 2009. Global Warming: The complete briefing. Cambridge University Press,

United Kingdom.

Hughes, T.P., Baird, A., Bellwood, D., Card, M., Connolly, S., Folke, C., Grosberg, R., 2003.

Climate change, human impacts, and the resilience of coral reefs, Science Magazine, 301,

929-932

Jones, PD et al. 2007, Observations: surface and atmospheric climate change. In Climate

Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth

Assessment Report of the Intergovernmental Panel on Climate Change: 235-336

Jones, A., Phillips, M., 2011. Disappearing Destinations: Climate change and future

challenges for coastal tourism. CPI Antony Rowe Ltd, Chippenham, United Kingdom, 1-6

Kendrick, G.A., Langtry, S., Fitzpatrick, J., Griffiths, R., Jacoby, C.A., 1998. Benthic

microalgae and nutrient dynamics in wave-disturbed environments in Marmion Lagoon,

Western Australia, compared with less disturbed mesocosms. Journal of Experimental

Marine Biology and Ecology, 228(1), 83–105

Marbà, N., Cebrián, J., Enríquez, S., Duarte, C.M., 1996. Growth patterns of Western

Mediterranean seagrasses: species-specific responses to seasonal forcing. Marine Ecology

Progress Series, 133, 203-215

17

National Oceanic & Atmospheric Administration (NOAA), 2014. Monthly/Seasonal Climate

Composites, Physical Sciences Division. Accessed 23/4/2014 from:

http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl

Novaczek, I., 1984. Development and phenology of Ecklonia radiata at two depths in Goat

Island Bay, New Zealand. Marine Biology, 81, 189-197.

Rasmussen, M.B., Henricksen, K., Jensen, A., 1983. Possible causes of temporal fluctuations

in primary production of the microphytobenthos in the Danish Wadden Sea, Marine

Biology, 73, 109–114

Sousa, W.P., 1979. Experimental investigations of disturbance and ecological succession in a

rocky intertidal algal community. Ecological Monographs, 49(3), 227-254

Sundbäck, K., Granéli, W., 1988. Influence of microphytobenthos on the nutrient flux

between sediment and water: a laboratory study. Marine Ecology Progress Series 43, 63–

69

Sundbäck, K., Jonsson, B., 1988. Microphytobenthos productivity and biomass in sublittoral

sediments of a stratified bay, southeastern Kattegat. Journal of Experimental Marine

Biology and Ecology, 122, 63–81

Sun, B., Fleeger, J.W., Carney, S., 1993. Sediment microtopography and the smale-scale

spatial distribution of meiofauna, Journal of Experimental Marine Biology and Ecology,

167, 73–90

Terry, R.D., G.V. Chilingar 1955. Summary of “Concerning Some Additional Aids in

Studying Sedimentary Formations” by M.S. Shuetsov. Journal of Sedimentary Petrology,

25, 229-234

Wasmund, N., 1984. Production and distribution of the microphytobenthos in the sediment of

Lake Mikolajskie. International Review of Hydrobiology, 69, 215–229

Wernberg, T., Russell, B.D., Moore, P.J., Ling, S.D., Smale, D.A., Campbell, A., Coleman,

M.A., Steinberg P.D., Kendrick, G.A., Connell, S.D. 2011. Impacts of climate change in a

global hotspot for temperatre marine biodiversity and ocean warming, Journal of

Experimental Marine Biology and Ecology, 400, 7-16

Wernberg, T., Goldberg, N., 2007. Short-term temperal dynamics of algal species in a

subtidal kelp bed in relation to changes in environmental conditions and canopy biomass,

Journal of Estuarine, Coastal and Shelf Science, 76, 265-272

18

Press Release

“Increasingly frequent storms threaten Cottesloe’s marine life”

The alarming impacts of climate change in Australia can be seen in our most popular beaches,

where the iconic reef systems and marine life that fuel our country’s tourism industry are

threatened by increasingly frequent and unpredictable storms. A local example and key

attraction of Perth is the suburb of Cottesloe and its excellent beaches. It was here that a

recent study was conducted, of which highlighted the need for further observation efforts to

fully understand the effect of storm disturbances on near-shore marine life. Marine science

students from the University of Western Australia held the study, and investigated the impact

of physical events such as winds, currents and wave energy on the growth and populations of

plants and animals on the seafloor. The study took place on four days spread across the 29th

March - 6th

April, with each of the four days focusing on specific groups of plants or animals.

This report in particular spotlights the students’ findings regarding the effect of storms on

Cottesloe’s underwater plants that inhabit the seafloor. Students compared recent years of the

plant data as well as recent years’ storm records, to try and identify a relationship between the

two. The study yielded results that were indefinite, and unsuitable for use in drawing

conclusions to explain the relationship between recent weather conditions and marine plant

populations. However, this in turn has emphasised the necessity for continued and amplified

study of this area and others similar to it, as there was a severe lack of previous data to aid

this investigation, and this will continue until large scale and long term observation efforts are

put into place to specify the nature of the effect of storms on near-shore marine life. These

studies are vitally important in gaining an understanding of just how much climate change is

affecting the earth’s wildlife. Once we can appreciate the harm we’re causing to our beloved

local beaches, it will pave the way for efforts to be made to reduce our carbon emissions and

alter our damaging lifestyles for the better of our beautiful coastline.