Macrophytes for wetland ecosystems management: Assessment of the spatial and temporal distribution of aquatic macrophytes as bioindicators of fishery production and nature conservation

Gabriella Leonor Vives Rivero

Institute of Landscape and Plant Ecology Faculty of Agricultural Science.

Topic background information / scientific relevance

The vulnerability of the wetland ecosystems is leading by anthropogenic pressures as deforestation, extreme climatic events, pollution, lack of monitoring and management, among others. Macrophytes play an important role in freshwater ecosystems, they are susceptible to changes related to anthropogenic stressors and can be accurate bioindicators of a water bodies' ecological state. These organisms improve the physical structure of aquatic environments and provide refuge and food to different organisms, including fishes. However, there is little progress in macrophyte's structural attributes research studies, it is to date even not considered as a component in the management conservation plans at some regions as Amazonian floodplains. Conversely, fishes have the most attention in research studies of aquatic ecosystems, due to fishery connect the aquatic ecosystem and human society.  Fisheries is one of the main economic activities for riverine communities and providing food security to thousands of people. Thus, to know and understand the links between the structural attributes of macrophytes and fishing productivity and the effects of fisheries on macrophyte stand structures are the main knowledge gaps that constitute the foundation of this study, in order to contribute to developing alternatives integrated management practices of the floodplain areas.

Challenges

This research focuses on the assessment of aquatic macrophytes as bioindicators of the water bodies' ecological state and its relationship with fishing productivity. Macrophytes are important components of wetland ecosystems due to provide physical structure and improving the water quality. In recent years, the number of studies on the role of macrophytes regarding to its structural attributes has increased in the Amazonian region but still little progress in research in the area. 

In areas such as the Amazonian floodplains, where fishing represents the main economic activity and source of nutrients for riverine communities, fishes had received the most attention. Fisheries act as integrators between the natural environment and human culture within the wetlands. Fishery production has reached about 179 million tons in 2018, with a total first sale value estimated at USD 401 billion around the world. Unfortunately, the Amazonian wetlands have a high unquantified fishing potential.

This proposal intends to develop a macrophyte index linking the study of the macrophyte distribution patterns with a socio-economic ecosystem service as fishery production, which could be useful to propose better integrative alternatives to management practices of wetlands and of importance for the riverine communities.

Objectives

O1. To assess the structural attributes like species composition, distribution, abundance, and diversity of aquatic macrophytes using unmanned aerial vehicles (UAVs).

(i) To assess the occurrence, richness, and diversity of macrophytes in different permanent floodplain lakes associated with the Ucayali River inside and outside from the Pacaya-Samiria National Reserve.

(ii) To assess the growth form and shoot density applying a visual image interpretation and to map macrophytes at the species level.

(iii) To assess the total macrophyte cover, providing reliable, visible and ecologically interpretable information on macrophytes distribution.

O2. To evaluate the influence of the abiotic factors on the spatial distribution patterns of macrophytes.

(i) What is the individual effect of the different abiotic factors (incl. fisheries), that determine the distribution patterns?

(ii) Does the interaction of the abiotic factors have a synergic, opposite, or additive effect on the macrophyte distribution?

O3. To evaluate the relation between the macrophytes distribution patterns and fishery production.

Which is the relation of the distribution of macrophytes and abiotic factors on:

(i)               fish catch rate during the floodplain discharge period and,

(ii)              fish species richness of the fish catch rate.

O4. To develop a macrophyte index for wetland ecosystems as an approach to fishery production assessment in local geographical conditions.