Sustainability of Coastal Resource Use in San Quintin, Mexico

Abstract

San Quintin, Mexico, provides a useful site for integrated analyses of material fluxes and socioeconomic constraints in a geographically isolated system. Natural resource utilization on the land is dominated by groundwater exploitation for cultivation of horticulture crops (primarily tomatoes). Irrigation exceeds water recharge minus export by a factor of 6. Resource utilization in the bay is dominated by oyster culture; food for the oysters is provided by tidal exchange of bay and ocean water. Consideration of oyster respiration and system respiration suggests that the present level of aquaculture is about 40% of the sustainable level. A "physical unsustainability index" (PhUI) was developed to measure the proportional departure of utilization of the most limiting resource for sustainability: 6 on land; 0.4 in the bay. Based on PhUI and measures of economic development, we conclude that aquaculture is more viable than agriculture.

Management of natural Ulva spp. blooms in San Quintin Bay, Baja California: Is it justified?

“…It could be possible that the combination of flooding and a short-term bloom would push the system past a tipping point, favoring ulvoids. Similarly, nutrient enrichment from agriculture practices involving the use of N and P fertilizers in the vicinity of the San Simon River Delta could also have favored macroalgal bloom development after the storm events [for fertilizer use in San Quintin Valley, see Aguirre-Muñoz et al (2001); nutrient discharge from fertilizer is about five times domestic waste discharge]. However, this is speculative, since none of these processes were described for San Quintin Bay.…”

Benthic nitrogen fixation in Zostera marina meadows in an upwelling-influenced coastal lagoon

“…San Quintín Bay (Fig. 1), a hypersaline coastal lagoon on the west coast of the Baja California Peninsula, Mexico (30º27N, 116º00W), has an average depth of ~2 m. Freshwater inflow is practically null as it is restricted to the San Simón stream that only delivers water during winters with higher than average rainfall (150 mm, Aguirre-Muñoz et al 2001). The dynamics and distribution of the water properties (salinity, temperature, dissolved nutrients, etc.)…”

“…en la laguna también sugiere que la fijación de N 2 es más intensa en los extremos internos del sistema (Sandoval-Gil et al 2015, Carriquiry et al 2016. Por otra parte, en bahía San Quintín, el N nuevo proveniente del océano adyacente disminuye desde la boca hacia el interior de la laguna (Camacho-Ibar et al 2003, Hernández-Ayón et al 2004) y los aportes continentales son considerados nulos (Aguirre-Muñoz et al 2001), por lo que las macrófitas de las zonas más internas probablemente presentan una mayor dependencia al N proveniente de los procesos internos como la amonificación y la fijación.…”

“…1) es una laguna costera hipersalina de ~2 m de profundidad promedio localizada en la península de Baja California, México (30º27N, 116º00W). Los aportes de agua terrestre son considerados nulos y se restringen al arroyo San Simón, que únicamente aporta agua durante inviernos con precipitación por arriba del promedio (150 mm, Aguirre-Muñoz et al 2001). La dinámica del sistema y la distribución de las propiedades del agua (salinidad, temperatura, nutrientes disueltos, etc.)…”

“…also suggests that N 2 fixation is more intense in the innermost parts of the system (Sandoval-Gil et al 2015, Carriquiry et al 2016. As the new N contributed by the adjacent ocean decreases from the mouth to the interior of the lagoon (Camacho-Ibar et al 2003, Hernández-Ayón et al 2004 and the continental inputs are null (Aguirre-Muñoz et al 2001), the macrophytes growing in the innermost areas are likely more dependent on N provided by internal processes such as ammonification and fixation.…”