MACROPHYTE DISTRIBUTION IN RELATION TO WATER QUALITY PARAMETERS

1.1 Introduction

Aquatic macrophytes are plants that are larger than most algae. The general term “aquatic plants” usually refers to aquatic macrophytes; but some scientists use it to mean both aquatic macrophytes and algae. They characteristically grow in water or in wet areas and are quite a diverse group. Some are rooted in the sediment while others float on the water surface and are rooted to the bottom. The term “aquatic macrophytes” includes largely flowering plants (angiosperms), some ferns and mosses (pteridophytes) and microscopic algae (storwort,e.g. chara and alga cladophora).

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitation of the study and Definition of terms.

1.2 Background of Study

Water quality of Ibadan river system in Nigeria is adversely affected and impaired by the discharge of domestic, agricultural and industrial wastes, which is the usual practice in Ibadan. This can be remedied with the use of aquatic macrophytes following the success recorded with the plant in this regard (Adeyemo et al., 2008). Cowx and Welcome (1998) listed the number of characteristics of aquatic plants which make them important to fish for conversion of toxic ammonia to usable forms(nitrates). Aquatic macrophytes are essential for a healthy fish stock to be maintained in a natural water body.

Opuszynski and Shireman (1995) pointed out that some plants or combination of plant species seems to be better fish habitats than others. Burgis et al., (1973) reported that, shallow marginal littoral with aquatic macrophytes contains a greater diversity of aquatic animals than the off shore open water areas.

Studies on aquatic macrophytes, and especially their ecology, were few in number before the 1960s (Thomaz et al 2008). Kio and Ola Adams (1987) reported the presence and spread of aquatic macrophytes on Nigerian water bodies that have aroused considerable national interest and concern especially in the Lagos lagoon and Okitiputa water ways. Man has tried for ages to control the excessive growth of aquatic macrophytes in both natural and artificial water bodies. However, eradication of the weeds has proved almost impossible. Turning these weeds to productive use will be desirable and several researches have so far been carried out Edie and Ho; (1969), Mbagwu and Adenifi (1985), Boyd (1968), Abdalla and Abdulhafeez (1969), Pirie (1960 and 1966).

Several of the parameters influenced by plants that have been observed to reach lethal limits, for common fresh water fish are dissolved oxygen, acidity and ammonia. Nather Khan (1990), reported that aquatic macrophytes absorb dissolved minerals and nutrients from polluted water and enrich water with oxygen during photosynthesis. Frodge et al (1995) measured dissolved oxygen and pH values in patches of Brasina Schreiber in the north west of the USA and found their values ranging from above (in open water) to below (in patches of the macrophytes) lethal limits (<1.0mg.L^-1 DO and <6.0 for pH) for rainbow trout (Oncorhynchus mykiss) within 10m of each other in the same lake. Rainbow trout in cages positioned at 1m depth below Nymphae odorata where dissolved oxygen concentration was consistently less than 4mgL^-1 were found dead within 12 hours.

Significantly mortalities of largemouth bass occurred at both the surface and at 1m depth in dense beds of the floating leaved macrophyte Brasinia schreiber, and in the bottom water of 2m or more depth of both floating leafed and submersed species, where oxygen concentration were less than 2mgL¹. The authors suggested that high densities of aquatic plants can have significant detrimental localized effects on fish and reduce the amount of habitat available to fish within the system. Eutrophication has become a problem in many countries. De Nie (1987) has reported long term changes in aquatic macrophytes of selected water bodies under the impact of eutrophication in Finland, Germany, the Netherlands, Poland, Switzerland, UK and USA.

Adesina et al (2010), discovered differences in the species of aquatic macrophytes on two lakes in southern Nigeria - the Ojirami dam and the Oguta Lake. Fewer aquatic macrophytes were encountered in the man-made Lake as against the natural Oguta Lake. They reported that siltation, human activities and age of the Oguta Lake as reasons for increase presence of emergent aquatic macrophytes on the lake. Despite the threats aquatic macrophytes may pose on water bodies, they can also be useful as lakes and ponds bordered by swamps and marginal vegetations are vividly exploited for municipals, industrial and agricultural wastewater treatment. They may also be used for the removal of agriculture effluents. Between 1984 and 1985, research was carried out on the highly eutrophied Lake Apopka in the U.S.A. using water hyacinth to remove nutrients from the lake. Channels that were stocked with water hyacinth consistently provided higher nutrient removal than the channel without water hyacinths (Reddy and DeBusk, 1987).

Boyd (1974), hinted the use of water hyacinth in the purification of water for fish culture that it can prove useful in treating effluents polluted with heavy metals. In static laboratory experiments, it (water hyacinth) rapidly absorbed Gold, Silver, Cobalt, Strontium, Cadmium, Nickel, Lead and Mercury. Water hyacinth can also absorb or metabolize Phenols and other trace organic compounds of the type commonly found in the drinking water supplies of many large cities FAO report (1979). Other aquatic macrophytes that can be use for water purification include duckweeds (Wolffia, Spirodela and Lemna) and Ceratophyllum dermesum. Aquatic macrophytes can also be used as food for fish and other aquatic animals like the Chinese grass carp (Ctenopharyngodon idella) has a remarkable capacity to eat aquatic weeds and a rapid growth with a palatable and nutritive flesh.

A few species of crayfish are exclusively herbivorous and appear to be promising for aquatic weed control and utilization like the red crayfish Procambarus clarkia that has been tried in the united state of America and it was found to eat all available vegetation if there is nothing better to eat Anon (1974). The manatee (Trichechus spp.) was also suggested by Allsopp, (1960 and 1969) as a potential biological method of aquatic weed control and utilization following its successful use in Guyana. This is further supported by Etherridge et al (1985) who investigated the consumption of aquatic plants by the West Indian Manatee. Aquatic macrophytes have been used in modern drugs and pharmaceutical industries Kio and OlaAdams (1987). They can provide shelter or refuge to zooplankton and restrict light penetration into deeper water leading to the death of submerged macrophytes. Daphnia spp was discovered to persist in dense macrophyte stands after their elimination in open water hence indicating that macrophytes can act as refuge for zooplankton (Stansfield et al., 1997).

Therefore, in Nigeria where the research was carried out, the activities that was conducted is to determine the water quality parameters given the presences of these macrophytes.

1.3 Statement of Problems

Investigation revealed that the presence and distribution of macrophytes in aquatic ecosystems can serve as indicators of the overall ecological health and water quality conditions. Macrophytes play a crucial role in maintaining the balance of these ecosystems by providing habitat, oxygenation, and nutrient cycling. Understanding the relationship between macrophyte distribution and water quality parameters is essential for effective management and conservation of aquatic systems.

The selected study area, along Ikot Akpaden Access Road in Akwa Ibom State, presents an opportunity to investigate the specific dynamics of macrophyte distribution in relation to water quality parameters in ponds. Ponds are often smaller, confined water bodies that can be more susceptible to environmental changes and anthropogenic influences compared to larger water bodies like lakes or rivers. Therefore, studying these ponds can provide valuable insights into the localized impacts of water quality on macrophyte distribution.

By examining the distribution pattern of macrophytes in the selected ponds, the study aims to identify any spatial variations in their abundance and diversity. This analysis can shed light on the factors that influence the establishment and growth of macrophytes within the ponds, such as light availability, sediment composition, and nutrient levels. Understanding the distribution pattern can also help identify potential hotspots of macrophyte growth and ecological significance within the study area.

1.4 Aim and Objectives of Study

The aim of the study is to examine the relationship between macrophyte distribution and water quality parameters in ponds located along Ikot Akpaden Access Road in Akwa Ibom State. In achieving this aim, the following specific objectives were laid out as follows:

1. To assess the distribution of macrophytes in the selected ponds along Ikot Akpaden Access Road;
2. To analyze the water quality parameters (such as pH, dissolved oxygen, turbidity, nutrient levels, etc.) in the selected ponds;
3. To determine the relationship between macrophyte distribution and water quality parameters;
4. To identify the dominant macrophyte species in the area under review; and
5. To evaluate the potential impacts of macrophyte distribution on the overall ecological health of the ponds.

1.5 Research Questions

The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:

• What is the distribution pattern of macrophytes in the selected ponds along Ikot Akpaden Access Road?
• What are the water quality parameters (pH, dissolved oxygen, turbidity, nutrient levels, etc.) in the selected ponds?
• Is there a relationship between macrophyte distribution and water quality parameters?
• Which macrophyte species are dominant in the study area?
• What are the potential impacts of macrophyte distribution on the overall ecological health of the ponds?

1.6 Significance of Study

The significance of this study lies in its potential contribution to the understanding of the relationship between macrophyte distribution and water quality parameters. The findings of this study can provide valuable information for the management and conservation of ponds along Ikot Akpaden Access Road. Additionally, the study can contribute to the existing knowledge of freshwater ecosystems and help identify potential ecological issues related to macrophyte growth and water quality.

This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.

1.7 Scope of Study

The scope of the research is focused on the Macrophyte Distribution in Relation to Water Quality Parameters. The study will focus specifically on selected ponds located along Ikot Akpaden Access Road in Akwa Ibom State.

The assessment will include the distribution of macrophytes and analysis of water quality parameters in these ponds. The study will not extend to other water bodies or regions outside the specified area.

1.8 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Research material: availability of research material is a major setback to the scope of the study.
3. Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
4. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).

1.9 Definition of Terms

Macrophytes:

Aquatic plants that are visible to the naked eye and rooted in the substrate of water bodies.

Water quality parameters:

Physical, chemical, and biological characteristics used to assess the condition of water, including dissolved oxygen, turbidity and nutrient levels.

Ponds:

Small bodies of standing water, typically shallow and often man-made, that support aquatic ecosystems.