Testing the predictive power of seagrass depth limit models

The power of equations predicting seagrass depth limit (Zc) from light extinction (Kz) was tested on data on seagrass depth limits collected from the literature. The test data set comprised 424 reports of seagrass colonization depth and water transparency, including data for 10 seagrass species. This data set confirmed the strong negative relationship betweenZc andKz. The regression equation in Duarte (1991) overestimated the realized seagrass colonization depths at colonization depths < 5 m, while there was no prediction bias above this threshold. These results indicated that seagrass colonizing turbid waters (Kz 0.27 m-1) have higher apparent light requirements than those growing in clearer waters. The relationship between seagrass colonization depth and light attenuation shifts at a threshold of light attenuation of 0.27 m-1, requiring separate equations to predictZc for seagrass growing in more turbid waters and clearer waters, and to set targets for seagrass restoration and conservation efforts.

[1]  D. Krause‐Jensen,et al.  Stability of eelgrass (Zostera marina L.) depth limits: influence of habitat type , 2005 .

[2]  W. Dennison.  Effects of light on seagrass photosynthesis, growth and depth distribution , 1987 .

[3]  Søren Laurentius Nielsen,et al.  Depth colonization of eelgrass (Zostera marina) and macroalgae as determined by water transparency in Danish coastal waters , 2002 .

[4]  T. Brosnan,et al.  Long-term improvements in water quality due to sewage abatement in the lower Hudson River , 1996 .

[5]  C. Duarte.  The future of seagrass meadows , 2002, Environmental Conservation.

[6]  J. Kirk,et al.  A THEORETICAL ANALYSIS OF THE CONTRIBUTION OF ALGAL CELLS TO THE ATTENUATION OF LIGHT WITHIN NATURAL WATERS , 1976 .

[7]  W. Kenworthy,et al.  Light requirements of seagrassesHalodule wrightii andSyringodium filiforme derived from the relationship between diffuse light attenuation and maximum depth distribution , 1996 .

[8]  D. Tomasko,et al.  Assessment of present and future nitrogen loads, water quality, and seagrass (Thalassia testudinum) depth distribution in Lemon Bay, Florida , 2001 .

[9]  Estimation of light requirement for the growth of Zostera marina in central Japan , 2003 .

[10]  C. Duarte.  Seagrass depth limits , 1991 .

[11]  Pablo Riera-Fernández,et al.  Biomass and primary production of a 8–11 m depth meadow versus <3 m depth meadows of the seagrass Cymodocea nodosa (Ucria) Ascherson , 2006 .

[12]  V. L. Johnson,et al.  Reversal of eutrophication following sewage treatment upgrades in the New River Estuary, North Carolina , 2005 .

[13]  M. Lorenti,et al.  Temporal dynamics and biomass partitioning in three Adriatic seagrass species: Posidonia oceanica, Cymodocea nodosa, Zostera marina , 2002 .

[14]  E. Lowe,et al.  Setting seagrass depth, coverage, and light targets for the Indian River Lagoon system, Florida , 2005 .

[15]  C. Duarte,et al.  Seasonality and depth zonation of intertidal Halophila ovalis and Zostera japonica in Ha Long Bay (northern Vietnam) , 2003 .

[16]  D. Krause‐Jensen,et al.  Predictive modelling of eelgrass (Zostera marina) depth limits , 2005 .

[17]  Frederick T. Short,et al.  Natural and human-induced disturbance of seagrasses , 1996, Environmental Conservation.

[18]  A. Schwarz,et al.  The photosynthetic light response of Halophila stipulacea growing along a depth gradient in the Gulf of Aqaba, the Red Sea , 2002 .

[19]  E. Koch.  Beyond light: Physical, geological, and geochemical parameters as possible submersed aquatic vegetation habitat requirements , 2001 .

[20]  Carlos M. Duarte,et al.  Submerged aquatic vegetation in relation to different nutrient regimes , 1995 .

[21]  J. Kirk.  A THEORETICAL ANALYSIS OF THE CONTRIBUTION OF ALGAL CELLS TO THE ATTENUATION OF LIGHT WITHIN NATURAL WATERS I. GENERAL TREATMENT OF SUSPENSIONS OF PIGMENTED CELLS , 1975 .