Marine life in an urban environment
by Crystle Wee
When we think about urban environments, we often fail to notice that our marine environments are just as, if not more, influenced by human development. While the focus in urban ecology has been largely dominated by discussions of terrestrial or freshwater environments, it is also vital to think of how urban development shapes marine ecosystems and habitats.
One of the key ways in which marine environments are degraded in Singapore is through widespread land reclamation and the alteration of our natural coastlines by constructed seawalls. After reclamation work is carried out, the area can be more prone to problems such as soil erosion, and this makes it necessary to build more infrastructure to reinforce coastal stability and mitigate erosion. Did you know that around 63% of Singapore’s coastlines are covered by seawalls? We need the seawalls to dissipate the energy in waves so it does not wear away our beaches and coastal areas. But seawalls are very harsh environments that may not support biodiversity the way natural coastal ecosystems do. Here’s a short infographic I created on land reclamation, which is what I feel is the biggest challenge to marine life in our coastal waters.
Look at changes in reclamation and development of our coastal areas from the 1950s to 2002. Since then, even more reclamation work has been completed, so much so that most of our coastal environments are different from what they were before (Images courtesy of Ria Tan, WildSingapore)
Marine biodiversity that persists despite the pressures of development
Reclamation and development have caused high rates of sedimentation and hence, very turbid waters and Singapore has lost more than 60% of its coral reefs. Nevertheless, Singapore still has an impressive array of marine life: at least 50 sea anemone species, 12 seagrass species and around 255 species of hard corals (Hilton & Manning, 1995; Chou, 2006; Huang et al., 2009). To put that in perspective, we have around a quarter of all hard coral species that can be found in the world!
Solutions to increase biodiversity in affected areas
The Experimental Marine Ecology Lab in NUS, led by Prof. Peter Todd, is researching methods to increase biodiversity along these sea walls by trying concrete tiles with different complex designs. Depending on the type of surface, the tiles can provide different ecological niches and spaces for a variety of marine organisms to colonise. I like this analogy…imagine a hawker centre in Singapore that only serves chicken rice. Now imagine a similar hawker centre, except this one also serves laksa, satay, roti prata and fishball noodles too! Which one do you think will attract more people? I know I’d definitely prefer the one with more variety! In a similar way, a marine environment with a variety of habitats will attract organisms with different habitat preferences. And so tiles with a greater variety of spaces, are more likely to provide suitable homes for a mixture of different organisms.
These concrete tiles can be a more favourable environment for marine snails and other organisms that typically live in rocky shore habitats. (Images courtesy of the Experimental Marine Ecology Lab, NUS)
If we want to better understand how human processes shape changes in the ecology and function of marine communities, then we need to focus more attention on urban ecology in marine environments. With more studies, hopefully we can think up better ways to develop sustainably and better consider the marine life we share our home with.
Chou L.M. (2006). “Marine habitats in one of the world’s busiest harbours,” in The Environment in Pacific Harbours, E. Wolanski, Ed. Dordrecht: Springer, 2006, ch. 22, pp. 377-391.
Hilton MJ and S. S. Manning, “Conversion of coastal habitats in Singapore: indications of unsustainable development,” Environmental Conservation, vol. 22, pp. 307-322, 1995.
Huang, D., Tun, K. P., Chou, L. M., & Todd, P. A. (2009). An inventory of zooxanthellate scleractinian corals in Singapore, including 33 new records. Raffles Bulletin of Zoology, 22, 69-80.
Loke LHL, Todd PA. “Structural complexity and component type increase intertidal biodiversity independently of area.” Ecology. 97 (2016) 383-393.
Loke LHL, Liao L, Bouma TJ, Todd PA. “Succession of seawall algal communities on artificial substrates.” Raffles Bulletin of Zoology. 32 (2016) 1-10.
Loke LHL, Ladle RJ, Bouma TJ, Todd PA. “Creating complex habitats for restoration and reconciliation.” Ecological Engineering. 77 (2015) 307-313.
Loke LHL, Jachowski NR, Bouma TJ, Ladle RJ, Todd PA. “Complexity for artificial substrates (CASU): software for creating and visualising habitat complexity.” PLoS ONE (2014) e87990.
Tan, R. (2008). “Loss of coastal ecosystems” Retrieved April 2017. http://www.wildsingapore.com/wildfacts/concepts/loss.htm