Abstract—Ecosystems are constantly subject to shifts among
multiple locally stable and unstable states. Such regime shifts or
bifurcations are fascinating ecological phenomena, involving
multiple causes and many variables that change at different
spatial-temporal scales, potentially altering the direction of
feedbacks. They are crucial for effective ecosystem management
because regime shifts may impair valuable ecosystem services
provided by nature and because recovery of desired states may
be difficult and costly. Lakes may undergo regime shifts between
two alternative steady states, oligotrophic or eutrophic, due to
the strong interaction between exogenous phosphorus (P) input
and endogenous interaction between water and sediment P.
Many lakes exhibit either a desirable oligotrophic clear-water
state with abundant macrophytes and low chlorophyll
concentrations, or an undesirable eutrophic turbid condition
with high chlorophyll concentrations and sparse macrophytes. A
regime shift from a clear-water oligotrophic state to a turbid
eutrophic condition may occur in response to a combination of
increased exogenous nutrient loading and a strong feedback
involving P release from the sediments. This paper presents
water and sediment quality data for a small shallow stagnant
lake in Selangor Malaysia indicating progressive deterioration
of water quality arising from intensification of eutrophication
due to accumulated nutrient loading from a relatively large
human settlement over three decades. It then provides numerical
simulations and analytical synthesis for explaining and
predicting the prognosis of lake eutrophication regime shifts.
The paper concludes with a practical and sustainable
remediation measure for rehabilitating lake eutrophication.
Index Terms—Algae, eutrophication, phosphorus, regime shift.
H. L. Koh is with the Jeffrey Sachs Center on Sustainable Development, Sunway University, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia (e-mail: firstname.lastname@example.org).
W. K. Tan is with the School of Mathematical Sciences, Sunway University, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia (e-mail: email@example.com).
S. Y. Teh is with the School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia (e-mail: firstname.lastname@example.org).
Cite: Hock Lye Koh, Wai Kiat Tan, and Su Yean Teh, "Regime Shift Analysis and Numerical Simulation for Effective Ecosystem Management," International Journal of Environmental Science and Development vol. 9, no. 8, pp. 192-199, 2018.