Effect of phosphate and ammonium levels on photosynthetic and respiratory responses of the red alga Gracilaria verrucosa

Influence of the population density of zooxanthellae and supply of ammonium on the biomass and metabolic characteristics of the reef corals Seriatopora hystrix and Stylophora pistillata

“…First, the decline in chlorophyll a content per zooxanthella with increasing population densities of zooxanthellae in Seriatopora hystrix is similar to the chlorosis experienced by nutrient-limited phytoplankton population~ (Falkowski 1980, Dawes et al 1984, Graneli & Sundback 1985, Cook et al 1988. Second, the addition of ammonium to the immediate environment of these corals resulted in a rapid increase in chlorophyll a content and the population density of zooxanthellae in S, hystrix and Stylophora pistillata.…”

“…The chlorophyll a content of zooxanthellae has been reported to increase with decreasing ambient light in analogy to sun-shade differences in terrestrial plant communities (Wethey & Porter 1976, Falkowski & Dubinsky 1981, Chang et al 1983. The reduced availability of inorganic nitrogen has also been demonstrated to reduce the chlorophyll content of marine algae (Falkowski 1980, Dawes et al 1984, Graneli & Sundback 1985. Given that the lowest chlorophyll contents are in zooxanthellae Living at the highest population densities, the second mechanism provides the best explanation of the variation of chlorophyll per algal cell with population density.…”

Comparative ecophysiology of bloom-forming macroalgae in the Indian River Lagoon, Florida: Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae

“…N:P ratios can differ widely among macroalgae, as a result of taxonomic differences in biochemical composition, nutrient assimilation characteristics, and environmental conditions. N storage occurs in rhodophyte phycobiliproteins (Dawes et al, 1984;Lapointe, 1981;Lapointe et al, 1984b;Lapointe and Ryther, 1978) and a N-limited plant (C:N N 13:1) will have the highest NH 4 + uptake rates (D'Elia and DeBoer, 1978;Hanisak, 1990) and NO 3 − suppression occurs when NH 4 + concentrations are 0.5-1.0 μM (D' Elia and DeBoer, 1978). Only in November 2011 sampling, did CIRL5 have NH 4 + concentrations greater than 1.0 μM (3.1 ± 0.01 μM), suggesting NH 4 + suppression.…”

“…readily assimilate all forms of dissolved inorganic nitrogen (DIN: NO 3 − and NH 4 + ) while rhodophytes such as, Gracilaria tikvahiae and Hypnea musciformis, preferentially assimilate NH 4 + (D'Elia and DeBoer, 1978;Ramus, 1982, 1984;Teichberg et al, 2007Teichberg et al, , 2008. Accordingly, whereas Ulva lactuca would be more competitive in a high N environment, G. tikvahiae (Teichberg et al, 2008) and H. musciformis (Dawes et al, 1976;Guist et al, 1982) are better adapted for growth in more N-limited areas due to broad tolerances to temperatures, light levels, and nitrogen storage in the form of non-photosynthetic accessory pigments, especially N-rich phycobiliprotein complexes (Dawes et al, 1984;Lapointe, 1981;Lapointe et al, 1984b;Lapointe and Ryther, 1978). Indicator species of rhodophytes and chlorophytes have formed extensive blooms in coastal waters impacted by nutrient pollution.…”

Seasonal changes inCystoseira myrica and phosphorus input at two sites of the Red Sea Egyptian Coast

“…De Boer (1981) reported that a general response to nutrient deficiency in algae is the accumulation of C-storage compounds. An inverse relationship between carbohydrates and protein (or tissue-N) has also been reported (Dawes et al, 1984).…”