13. From Totem Poles to Tea Cups: Returning Home

I have finally come to the end of my year abroad and am sitting in my half packed up kitchen, surrounded by suitcases and organizational chaos. I have 2 days until I get kicked out of my UBC accommodation and have to be on my way. I feel so happy and settled here; it seems surreal that I won’t be coming back and that I won’t see half of these people ever again.

Sunny walk on the beach for my 21st birthday, with Vancouver in the background

This week has been a hectic mix of deadlines, life admin and emotions - so trying to collect my thoughts and write a final summary blog is a bit of a struggle. I have had an absolute ball here in Canada and ironically it is because of this that I’m finding it so hard to say goodbye. I have found such a strong niche here and felt a sense of community and belonging that I never felt at UCL.

Everyone in their UBC 'Thunderbird" T-Shirts for the big Homecoming football game

Academically, I have had the freedom and ability to pursue the topic areas that really get me out of bed in the morning. I’ve got stuck into forestry, sustainable agriculture, plants and soils. (I have just submitted my module options for UCL next year and was sad that I won’t have the opportunity to pursue these subjects further when I get back home). My professors’ enthusiasm and support, the communal and caring classroom environment, and the continuous assessment structure have enabled me to thrive and caused my self-confidence to grow.  I have spent limited time sitting alone in libraries, have read hardly any dense literature, have had an amazing number of contact hours and have not felt particularly stressed at any point during the year. Yet, I feel like I have learnt more than I did in either of my two years in London, have achieved grades of almost all 80% or above and have managed to have time to do 5 million other non-academic things as well. 

View from a hike in Sqaumish, just an hour north of Vancouver

Socially, I have met an absolutely wonderful group of people: both local and international. I think perhaps the type of people that choose to go to UBC are a self selecting group, but I guess some of it also comes down to luck. I have formed such close friendships here with people scattered all over the world. They are what have made UBC my home away from home, and it’s hard to accept that we must now all go our separate ways.

Standing in front of the UBC sign before the Exchange Club end of year gala

In terms of the location, I have loved the UBC campus with its beautiful walkways, its own gorgeous beach and adjacent forest. Vancouver has been a great city to explore and its proximity to some of the most glorious, wild and expansive landscapes has been truly unique. The overarching attitude towards getting out and adventuring has been amazing to become part of and I have spent numerous happy weekends hiking and exploring with everyone.

Views from the Rose Garden on Campus

A weekend hiking in Whistler

I’m going to miss the whole experience so much – I wish I could do it all over again and wouldn’t hesitate for a second before recommending it to someone else.

Bye UBC, Vancouver and Canada – you’ve been a blast!

12. Integrated Plant-Animal System

In this post I am going to outline (as simply as possible) the integrated plant-animal system that I designed for my Agroecology module. The idea is that plant and animal production systems compliment each other and by combining the two you can reduce the need for external resource inputs (e.g. manure can be used as fertilizer for plants).

My system aim:

Feeding the global population whilst not crossing environmental planetary boundaries is one of the greatest challenges that we are faced with today (Rockström et al. 2009). We need to be able to grow more food on less land, whilst using fewer resource inputs. A shift to a more sustainable diet is arguably going to be essential to help us overcome this problem. As the world develops, more and more people have meat and dairy heavy diets, which are much less sustainable than plant based diets due to the loss of energy up the food chain from one trophic level to the next.

However, not everyone wants to become vegetarian and the environmental impact of all meat production is not equal as different animals have different nutritional and energy requirements. My project aims to find and produce a more sustainable animal based protein source, which is integrated with plant production systems.

What is my system?

I have designed an aquaponic system consisting of three primary biological components:

1. Nile Tilapia - a species of fish

2. Duckweed (Lemna minor) - a species of floating aquatic plant

3. Aerobic bacteria

Aquaponics refers to the integration of aquaculture (raising fish) with hydroponics (the soil-less growing of plants). Aquaponic systems recycle nutrients (primarily nitrogen) between fish and plants to reduce the need for external nutrient inputs. At the most basic level, fish excrete ammonia (a plant unavailable form of nitrogen). Bacteria convert ammonia in the fish wastewater to nitrates (a plant available form of nitrogen). This nitrate rich water is used to grow plants. This water is then recycled back into the fish tanks. Excess ammonia is toxic to fish and therefore, this process also reduces the need for water detoxification (Rakocy et al. 2006).

Usually, both the fish and the plants grown in an aquaponic system are marketable outputs and the fish are fed using external inputs of feedstock (often fishmeal made from ground up fish). However, in my system the plants grown will not be a cash crop but instead will be used as feedstock for the fish. Although this reduces the profitable outputs of the system, it also reduces the expensive and arguably less sustainable inputs to the system, thus creating a more self-sufficient nutrient loop.

The output product of the system is tilapia fish. These grow quickly and have unusually high feed conversion ratios (close to 1:1), meaning they use feedstock energy very efficiently (Ridha, 2000) Tilapia are omnivorous and will be fed predominantly on duckweed: a fast growing, environmentally tolerant floating aquatic plant with a protein content of up to 40% (Leng et al. 1995)!!! The use of duckweed reduces external feedstock inputs, thus reducing cost, increasing self-sufficiency and reducing the environmental impact of feedstock production. Feeding the fish plants as opposed to ground up fish also reduces energy losses up the food chain.  The nutrient rich wastewater from the fishponds will be fed through an aerobic digester or ‘bioreactor’ that will convert organic plant unavailable nitrogen to inorganic plant available nitrogen. This water will then be fed into a system of shallow pans that will be used to grow the duckweed. The duckweed will then be harvested with a simple net and fed wet to the fish.

Infrastructural system design:

• The whole system will operate within a heated greenhouse.
• Tilapia will be grown in large insulated tanks.
• A swirl separator will be used to separate solids out of the fish tank wastewater.
• The liquid from the swirl separator will then be fed into a bioreactor containing the aerobic nitrifying bacteria. 
• The nitrate rich water from the bioreactor will then be pumped to a series of shallow stacked plastic trays that will be used to grow the duckweed. (Duckweed is a floating plant and therefore can grow in a little as 3mm of water!! Their shallow size and stacked setup maximize the surface area available for growth).
• Water from these trays will then be fed back into the fish tanks.

References:

Leng, R., Stambolie, J. & Bell, R., 1995. Duckweed - a potential high-protein feed resource for domestic animals and fish. Livestock Research for Rural Development, 7(1).

Rakocy, J.E., Masser, M.P. & Losordo, T.M., 2006. Recirculating Aquaculture Tank Production Systems: Aquaponics — Integrating Fish and Plant Culture. Southern Regional Aquaculture Center, (454).

Ridha, M., 2000. Preliminary study on growth, feed conversion and production in non-improved and improved strains of the Nile Tilapia. Aquaculture, Fisheries and Marine Environment Department, Kuwait Institute for Scientific Research.

Rockström, J., Steffen, W. & Noone, K., 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Societty, 14(2), pp.32–65.