Water quality and tidal induced changes effects on the zooplankton community in the Area of Multiple Use Hawaii, mangrove channel in South Pacific Guatemala

Abstract

Abstract:

The zooplankton community of The Area of Multiple Use Hawaii (AUMH), South Pacific Coast of Guatemala mangrove channel ecosystem was studied in the dry season between February and March 2011. Zooplankton samples were taken during two lunar cycles, four tidal cycles (flood, high water (HW), ebb, low water (LW)), at four different sites. For each sampling occasion, salinity, pH, dissolved oxygen and temperature were measured. Levels of pH and dissolved oxigen were significantly different between 3 sites. The zooplankton community was dominated by Nauplius-larvae, Calanoid copepod and Zoea-larvae. Zooplankton abundance and diversity were significantly higher at spring tide hauls compared to neap tide; in contrast, there was no difference when comparing the different sites. Because of these results, the amount of water moving through the estuary seemed to be a determining factor controlling the zooplankton community composition.

Popular science summary:

Mangrove water quality and tide effects on zooplankton

Mangroves are highly productive ecosystems characteristic of tropical and subtropical coastlines. They are recognized as important, yet undervalued and poorly understood ecosystems. Mangroves are known as essential nursery breeding grounds for zooplankton, which provide a fundamental connection between the microalgae and juvenile fish. Despite their important ecological role, few efforts have been made to analyze the zooplankton community in Guatemala. The studied area is located in the southern part of the Pacific coast of Guatemala. This mangrove ecosystem is home to the second largest mangrove wetlands on the Pacific coast of Guatemala, which provides vital conditions for many species of economic and biological importance, such as fish and shrimp. This area considered to be threatened with 3 major factors: 1. No artisanal fishing regulations, 2. No waste water treatment and 3.There is no recollection programme for solid waste.

For this study 4 sites were selected and the samples were taken at the end of the dry season, with just a few hours of rain recorded. Zooplankton samples were taken during 2 lunar cycles between February and March 2011. For each sampling occasion, salinity, water temperature, dissolved oxygen and pH were recorded. Later, zooplankton specimens where analysed and counted in a laboratory. The data obtained was then analyzed using statistical software.

Results and Conclusions

Dissolved oxygen and pH varied significantly during the sampling period, but none had values that would affect the zooplankton community negatively. The zooplankton community was dominated by small crustacean larval species and fish larvae were also caught. Zooplankton abundance and diversity was not different between the sites. Both diversity and
abundance had higher values for the spring tide lunar cycle, and abundance was also different between tides, with no clear pattern on a specific tide.

Because the abundance and diversity of zooplankton did not vary between the sites it can be recognized that the water quality had no effect on the zooplankton. The amount of water moving within the estuary through the changing tides and lunar cycles seemed to be an important factor controlling the composition of zooplankton. However its not certain
if this is the driving factor or if it’s the result of other factors acting together.

Advisor: Per Carlsson
Master´s Degree Project - Marine Biology, 30 credits
Department of Biology, Lund University

• author: Layton, Kristoffer
• supervisor: Per Carlsson
• organization: Degree Projects in Biology
• course: BIOM21 20111
• year: 2012
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 3633116
• date added to LUP: 2013-04-12 10:24:32
• date last changed: 2013-04-12 10:24:32