Short-Term Dinoflagellate Bloom in a Shrimp Pond in Bahía de La Paz, Gulf of California

Abstract

From mid-August to mid-September 1998, a dinoflagellate bloom in a shrimp pond near La Paz, Baja California Sur, was studied. Daily samples were taken of phytoplankton, dissolved oxygen, nutrient concentrations, photosynthetic pigments and proteins. The bloom occurred at temperatures of 29.7 to 33.2 °C. High densities of a Scrippsiella-like dinoflagellate (15.9 × 10⁶ cells/L) occurred on the first day of sampling, reaching a peak of 249 × 10⁶ cells/L on Day 13, and declining to 4 to 7 × 10⁶ cells/L by Day 26. Chlorophyll a varied from 8.63 mg/m³ on Day 4 to 141.38 mg/m³ on Day 13. Total nitrogen varied widely (0.2–11.50 μM) while phosphates peaked only once on Day 13 (4.14 μM). Proteins ranged from 523 to 6387 μg/L; the latter value occurred two days after the maximal peak of nitrates and coinciding with the highest level of phosphates. Fertilizers added to the ponds increased nutrient concentration and stimulated phytoplankton growth. In turn, the food supply to cultured shrimp noticeably increased throughout the bloom.

Keywords:

• Gulf of California
• Bahía de La Paz
• shrimp ponds
• dinoflagellate blooms
• excess nutrients
• photosynthetic pigments
• proteins

Acknowledgments

We thank J. R. Hernández-Alfonso (Centro Interdisciplinario de Ciencias Marinas–Instituto Politécnico Nacional) for his assistance with protein analysis; M. C. Ramírez-Jáuregui (Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México) for help in the literature search. I. Fogel (Centro de Investigaciones Biológicas del Noroeste) provided valuable editorial assistance. Acuacultores de la Paz permitted collection of samples during the bloom. The study was funded by Instituto Politécnico Nacional (projects Secretaria de Investigación y Posgrado-20071252, 20080711, and 20082279), the Centro de Investigaciones Biológicas del Noroeste (projects PC3.2 and PC3.1), and Consejo Nacional de Ciencia y Tecnología (Secretaría de Medio Ambiente y Recursos Naturales-Consejo Nacional de Ciencia y Tecnología 2002-COI-0318-A-1, Sistema Nacional de Investigadores-90102, Secretaria de Educaión Pública 2007-84064). I. G. L. and C. J. B. S. are fellows of Comisión de Operación y Fomento de Actividades Académicas and Estimulos al Desempeño Docente.