Team:HK SSC/Human Practices

The main goals of our human practices are to know more about the different stakeholders regarding algal blooms, educate them about the ecological value of cyanobacteria and gather their opinions on our project. To achieve this, we conducted 11 interviews with local fish and oyster farmers, with some recorded below. .

Lan is a fish farmer from Yuen Long, rearing Aconitum, Redbelly Tilapia and mud carp. Algal blooms often occur when her ponds become turbid, causing her some fish to lose their appetite. She suspected it to be caused by toxic substances from algae. However, she admitted that certain species, including Bighead carps, feed on algae. Lan confesses that it is hard to strike a balance between algae and the toxin concentration. With her current means, she can only clear out an entire pond just to disinfect it with sunlight and tea ash.

Fig. 1 Lan teaching us on how to use a fish net

Fig2. We were able to experience being a fish farmer in Lan’s fish farm

Mr To, another fish farmer, says fish are highly sensitive to their surroundings and will easily die off from slight and sudden environmental changes. Thus, toxic algal blooms are highly damaging to fisheries.

Fig. 3 Team members meeting with Mr To

Fig. 4 Algae infested pond at Mr To’s farm

Mr Yeung, owner of Yeung’s Fisheries Ltd, says algal blooms usually occur due to excessive fish excrement in ponds. He stated that there are both toxic and non-toxic algal blooms. He was able to distinguish the difference by the smell of the pond. He told us that the toxic substances produced in algal blooms can remain in the pond for a long period of time. He once experienced massive fish loss which was susceptible to the remains of toxins after an algal bloom. Currently, Mr Yeung uses filter feeder fish and ripe lime powder in addition to sunlight and tea ash when controlling algal blooms. However, he finds all the above methods highly inefficient and inconvenient due to the need to clear out the entire pond.

Fig. 5 Algal bloom in Mr Yeung’s farm

Integrating ideas

After conducting the interviews and learning about the limitations of current algal bloom control methods, we integrated these ideas into our project and decided to use dCas9 enzyme as it is an efficient platform for gene silencing. Instead of clearing out an entire pond, fish farmers could simply use the enzyme to silence detrimental genes with high efficiency.

Collecting opinions

We were also able to collect opinions from fish farm and oyster farm owners. From most of their responses, we understand that revenue is a major concern for fish and oyster farmers. Therefore, using biological means of removing toxins should not cause any harmful effects on fisheries, as it may decrease their value, and such methods should not be costly.

Education

During the interviews, we also taught them how to distinguish between cyanobacteria and green algae depending on the appearance and explained how toxins produced by cyanobacteria could be harmful. For example, cyanobacteria can come in red, blue, green and brown. We also educated them on the ecological value of cyanobacteria.

Fig. 6 Interviewing and educating local fish farmers about the harms and benefits of algae

Our survey has occurred successfully with a total of 69 respondents who answered all four questions. The questions and survey results have been enlisted below:

From the graphs above, 10.10% (7)of the respondents have heard about cyanobacteria while 89.90 % (62) have not. On the other hand, 97.10% (67)of respondents have heard of algal blooms while 2.80% (2) have not. Also, algal blooms occur in the proximity of the living environment of 75.40% (52) of respondents. Also, 58% (40) of respondents will drink water from a stream in the wild.

While most of our respondents (89.90%) have heard of algal blooms, only 10.10% have heard about cyanobacteria. It can be inferred that the public lacks the ability to distinguish between the two. While green algae have nutritious values beneficial to marine life, cyanobacteria produce neurotoxins and toxify waters. Hence, the inability to distinguish between the two may be lethal to both the public’s and ecological health. When they drink water from streams in the wild (which 58% respondents admit in doing), they may be intoxicated due to the lack of ability to distinguish between the two. Furthermore, algal blooms occur in proximity of where 75.40% respondents live. This emphasizes the magnitude of which both cyanobacteria and algal blooms affect people’s lives on a daily basis. Our human practices involves educating people who face problems about these aspects on a daily basis (such as fish farmers) about differences between the two. With such ability, they may be able to cultivate more optimum water conditions which are beneficial to their fish. We have also educated them about Microcystis Aeruginosa and its harmful effects. which is greatly applicable and beneficial to the environment and learners in both an ecological and personal perspective.

In conclusion, our local fish farmers have informed us of their current methods of algal removal and their various limitations. This has inspired us to make a specific, efficient gene silencing platform in order to meet their needs. In return, we educated them on the ecological benefits of algae. Finally, we would like to wholeheartedly thank all interviewees on generously sharing their experiences with us.

Special thanks to all interviewees:

Mr To Kai Ching
Ms Fung Hueng Lan
Ms Zhou Yin Di
Ms So Sam Mui
Mr Yeung Sui Leong
Mr Chen Tian Cai
Mr Chen Ru En
Mr Chan Kam To
Yeung’s Fisheries Ltd
Members of HK Fishpond Conservation Scheme
HK Fishpond Conservation Scheme
Members of Greenpeace HK