4.1.7 Seaweed networks
The First Law of Ecology: Everything Is Connected to Everything Else
One of the four informal laws of ecology by Barry Commoner, The Closing Circle: Nature, Man, and Technology (Commoner and Egan, 2020, p.29).
Figure 156. (Top image) Screenshot of the Kumu map at a seaweed scale and its relationship to Kanten/The Edge scale (Kumu, 2020). It encompasses five mini-nodes, such as maps pertaining to issues around industry, anthropogenic, cultural, ecological and urban development as pressures that impact marine life – such as seaweed.
(Bottom image) A cyclic relational diagram (made in Kumu) of all the living and nonliving, human and nonhuman actors influencing the outcome of marine NbS in the inner Vejle Fjord (Kanten/The Edge proposals).
The cyclic process above illustrates the different factors that need to be considered to implement NbS with seaweed successfully. For instance, the crab and starfish populations need to be managed --> ensure the predatorial fish population is healthy --> provide nurseries for the fish through stone reefs and artificial houses --> ensure the water clarity is good so that eelgrass/seaweed can grow and provide habitat for fish --> ensure nutrient load from agriculture (pig farming) is limited --> etc.
Having gone through the micro, meso, and macro scales of the KUMU map, the final scale I will discuss in this section is unlike those addressed above, as I here focus on the intricate networks of seaweed, thus moving back again from the global to the microscopic. One of the key learnings from interviewing marine biologists is that when thinking about “Urban Seascaping” projects such as Kanten/The Edge, it is necessary to account for how complex and interrelated the ecosystems are. Simply put, when dealing with the marine realm, it is not as simple as allocating a plot of land to plant trees and flowers. The ecological collapse of the Vejle fjord happened in the eighties mainly due to agricultural activities (also commercial fishing[232]), which resulted in poor ecological conditions that destroyed crucial habitats for small fish (Fjeldsø Christensen, 2021). Only a few big predatorial fish are present to eat the crabs, resulting in an imbalanced food chain in the water (Fjeldsø Christensen, 2021) (see Figure 156). The absence of predators resulted in an explosion of crab and starfish populations that consumed vast amounts of eelgrass forests, mussel beds and seaweed as food (see Figure 157). Now, without human intervention[233] to proactively fish out these crabs and starfish, they will hinder marine nature restoration efforts by Sund Vejle Fjord (Fjeldsø Christensen, 2021).
*NB: The following image is embedded into the above "Seaweed Scale/Networks" node (scroll down the information window plane in Kumu). Click on the blue-bordered screenshot images to be directed to the original videos.
Figure 157. “The Ecological Pressure node” showcases the impacts of floating particles (agricultural runoff – Phosphorous and Nitrogen nutrients) (Seghetta et al., 2016).
(Second row of images) Due to the ecological imbalance in Vejle Fjord, there is an exploding population of crabs and starfish. Marine biologists are proactively fishing out the local crabs to help minimise the damage to new eelgrass plantations. Starfish hinders Sund Vejle Fjord’s efforts to reinstate mussels on the sea bed and lines via floating buoys by eating through them[234]. Image credit: Sund Vejle Fjord (n.d.).
(Third and fourth row) Sund Vejle Fjord project documented 70 hours of video scanning the bottom of Vejle fjord; it is mostly a lifeless area with mud and sand making most of the conditions. However, areas where eelgrass, blue mussels and rock reef have been reinstated are showing signs of improvement, where diverse marine life have come back. Due to the muddy sea bed condition of the Vejle fjord, coconut mats are used to ensure that the mussel beds do not sink to the bottom and disappear in the mud (Organo Quintana, 2020). Image credit: Sund Vejle Fjord (n.d.).
(Bottom row – Left to Right) Young eelgrass plantations are grown in containers to help them settle and grow bigger before being planted onto the seabed. Stone reefs installed in July 2022 are already showing signs of seaweed (Savtang, blæretang, Sukkertang) monitored in inner Vejle Fjord in November 2022, despite the fact that the water conditions are not good. Image credit: Sund Vejle Fjord (n.d.).
(Extracted from Kumu Multiscalar map – Seaweed scale node).
Understanding these “micro-scale” ecological food chains and their relationship to anthropogenic activities such as agriculture is necessary as they impact any NbS initiatives at Kanten/The Edge. Thus, designers (LUPD disciplines) have an important role in finding creative and artistic ways to reinstate the ecological balance in Vejle Fjord by designing for marine life. For instance, design proposals could aid in creating artificial nurseries for fish while preventing crabs from entering, a frame to support young eelgrass[235] plantations, hard materials and shapes that respond well with seaweed, etc. These human interventions can speed up and improve the success of nature-based solutions and nature restoration efforts while finding creative ways to communicate the initiatives happening below the water (i.e. see SUPERFLEX’s projects in Figure 94). It is important that initiatives like Kanten/The Edge that seek to convey marine nature to the wider public put their best foot forward to show the invisible world underneath and not be left with a lifeless marine dead zone.
[232] While commercial fishing is banned in the Wild and Nature Reservation (Vejle Inderfjord Vildtreservat) in the inner Vejle fjord, recreational fishing is not (Fishing in Denmark, 2021).
[233] Due to proactive restoration efforts by the Sund Vejle Fjord project, sea trout populations are found to be on the rise, with the fish lingering around the eelgrass meadows and new rock reefs strengthening the argument of the importance of creating habitats for the local fish stock (Sund Vejle Fjord, 2022).
[234] Sund Vejle Fjord has been growing mussels on lines (floating buoys), so crabs can not reach them. However, what marine biologists have noticed is that due to ocean warming, the starfish eggs are spawning earlier in the season than usual (before the mussels develop to grow hard shells). Thus, these starfish eggs can attach to the mussels, grow up and eat mussels on these lines (Sund Vejle Fjord, 2022).
[235] During strong storms, young eelgrass plantations struggle to withstand the impact of the force. Therefore, until they form strong roots, they need support structures that can help mitigate the impact. Furthermore, eelgrass replanting/propagation is a manually laborious task, thus, an expensive venture. It requires divers to separate existing eelgrass shoots to replant them elsewhere by hand. Therefore there is a limit to how much eelgrass people can propagate from existing adult eelgrass (Organo Quintana, 2020; Fjeldsø Christensen, 2021). For these reasons, an artificial habitat/nurseries created for fish (which cannot be eaten by crabs) could speed up the process and increase the success of providing protection for small fish while eelgrass plantations take a longer time to mature.