Assessing trophic state of an endorheic tropical lake: the algal growth potential and limiting nutrients

The algal growth-limiting nutrient of lakes located at Mexico’s Mesa Central

“…However, López and Dávalos Lind (1998) found an interesting spatial variation of the limiting nutrient (including N) at a wider geographical scale beyond the water body, including the tributary and the outlet. N limitation also occurred in some cases (Dávalos, 1989, Hernández et al, 2001Ramos-Higuera et al, 2008) as well as NP co-limitation (Bernal-Brooks et al, 2002a, 2003. For Lake Pátzcuaro, the results obtained here deviated from the previous study (Bernal-Brooks et al, 2003), as the open waters showed an N limitation consistently for Lake Pátzcuaro 2, 3 and 4.…”

“…Thus, both the aforementioned features articulated each other to produce severe impacts for the aquatic ecosystem and new in-lake scenarios of stress for the local species. In turn, Lake Zirahuén, the so-called blue lake, has lost its oligo-mesotrophic status (Bernal-Brooks 1988, 2002a and has become rather eutrophic. The change of an NP to a temporal N limitation during the dry season may indicate the presence of nutrient loadings coming from the watershed, in such amounts that are unable to be assimilated by the lake self-depuration mechanisms.…”

Limnology in Mexico

“…The stratification period lasts eight (Lake Zirahuén, Bernal-Brooks et al, 2002b), nine (lakes Alchichica and Atextac, Alcocer et al, 2000a andMacek et al, 1994, respectively) and up to 11 months (Lake Santa María del Oro, Filonov et al, unpublished data). In contrast, the shallow eutrophic lakes remain oxygenated all over the water column accordingly to the warm-polymictic mixing type (Table 4).…”

Responses to a warming trend and “El Niño” events in a tropical lake in western Mexico

“…These included the low silica values in January 2009 and the low DIN and SRP values leading to N and P co-limitation in surface waters in May 2009. C. ocellata is a species that flourishes in similar conditions in lake Zirahuen (Tavera and Martinez Almeida 2005), with P and N co-limitation (Bernal Brooks et al 2002) and low silica values (Caballero and Vázquez, unpublished data). The deep water chlorophyll maxima in August 2009 and the high abundance of C. ocellata in the metalimnion during August and October 2009, indicates that under poorly mixed conditions this species is finding higher nutrient availably in the deeper waters as a survival strategy given the low nutrient concentrations in the epilimnion (Davey and Heaney 1989).…”