ANSWER: 
Problem faced include; habitat loss and degradation, disease outbreak, invasive species, pollution, over‐exploitation/overfishing, climate change etc.
EXPLANATION:
Problem:
Habitat loss and degradation, disease outbreak, invasive species, pollution, over‐exploitation/overfishing, and climate change are notable problems experienced by freshwater and marine fishes.
Solution:
Anthropogenic activities and stressors that rapidly threaten freshwater and marine fishes are curbed through legislation and other means to prevent extinction of fishes. 
Through conservation programs that plans for individual species to more species of entire faunas of a particular location also boost population size and prevent hunting of threatened or endangered species in both realms.
Overtime, genetically modified fishes which can develop resistance to diseases are introduced to the realm.
Moreso, waste channels through which pollutants gets into the water bodies are well-treated for safety of fishes.
 
        
             
        
        
        
Adaptation is the correct answer
        
                    
             
        
        
        
Answer: Options A, B, D and E. 
A. Process for initiating.
B. standard reporting format.
D. process for synthesizing the body of evidence.
E. process for finding and assessing individual studies.
Explanation:
Systematic review is a scientific process which combines findings from research using random sampling of works from different source of a particular subject and integrating them into a powerful and clinically useful report to guide practice. It is a form of paradigm that guides and aids further research in a particular field. 
However, there are components to be considered in other to create a perfect resolution. Initiation of the process begins with gathering of research from different source. 
Then, individual research work is also accessed to derive facts and putting up a standard report to explain the total discovery. 
 
        
             
        
        
        
Answer:
highlighted in bold above, are a struggle for existence, variation and inheritance
Explanation:
i hope this helps
 
        
             
        
        
        
Answer:
Fossil fuels specifically natural gas 
Explanation: