| effects of el niño on distribution and reproductive performance of black brant. | climate in low-latitude wintering areas may influence temperate and high-latitude breeding populations of birds, but demonstrations of such relationships have been rare because of difficulties in linking wintering with breeding populations. we used long-term aerial surveys in mexican wintering areas and breeding areas in alaska, usa, to assess numbers of black brant (branta bernicla nigricans; hereafter brant) on their principal wintering and breeding area in el niño and non-el niño years. we us ... | 2006 | 16634306 |
| mortality rate estimation for eelgrass zostera marina (potamogetonaceae) using projections from leslie matrices. | the main goal of this study is to provide estimations of mean mortality rate of vegetative shoots of the seagrass zostera marina in a meadow near ensenada baja california, using a technique that minimizes destructive sampling. using cohorts and leslie matrices, three life tables were constructed, each representing a season within the period of monthly sampling (april 1999 to april 2000). ages for the cohorts were established in terms of plastochrone interval (pi). the matrices were projected thr ... | 2008 | 19419024 |
| an economical non-destructive method for estimating eelgrass, zostera marina (potamogetonaceae) leaf growth rates: formal development and use in northwestern baja california. | seagrass beds provide much of the primary production in estuaries; host many fishes and fish larvae, and abate erosion. the present study presents original analytical methods for estimating mean leaf-growth rates of eelgrass (zostera marina). the method was calibrated by using data collected in a z. marina meadow at punta banda estuary in baja california, mexico. the analytical assessments were based on measurements of leaf length and standard regression procedures. we present a detailed explana ... | 2008 | 19419023 |
| trace metals in sediments and zostera marina of san ignacio and ojo de liebre lagoons in the central pacific coast of baja california, mexico. | san ignacio and ojo de liebre lagoons in central baja california, mexico are nursery and grazing grounds for whales and turtles. ojo de liebre lagoon also supports a salt mine operation. by concentrating trace metals via evaporation, this activity might harm biota. consequently, salt mining might be incompatible with the lagoon's ecological role. eelgrass can incorporate these elements and reroute them to other organisms. trace metals in sediments (cd, co, cu, mn, ni, pb, zn, and fe) were measur ... | 2008 | 18188634 |