I have spent the past few weeks in northern Europe, visiting Friends of A Rocha Germany and A Rocha Sweden. It has been great to see friends from past work and meet many new friends committed to caring for God’s world. Dr Dorothea Seeger is a good friend and a leader in the Germany Friends group – she is also a marine biologist who was recently featured in A Rocha’s podcast Field Notes Episode 44. Doro was part of our work in Kenya, focusing on seagrass and marine algae biodiversity and an author on our big marine biodiversity of Watamu Marine National Park paper. She also was part of a fun trip to the Mediterranean where we explored possibilities for marine conservation there. This resulted in our microplastics projects in France, Portugal, Kenya, and USA along with A Rocha participating in the Great Global Nurdle Hunt each year. I flew in to Amsterdam and then took the train to Bremen to meet Doro so she could show me her place – the Wadden Sea.
Doro and I on our recent trip to the Wadden Sea - maybe next visit in the summer!
If you are like me, you probably didn’t learn much about that sea or may even know that Germany has a marine coastline. Yet the Wadden Sea has been utilized by humans for the past 10000 years. In researching this part of God’s ocean, I came across an interesting paper by Lotze et al. (2005) that synthesized data from many studies including some that looked at historical data dating back to just after the last ice age. They put together an amazing table (the article can be downloaded for free) that summarized evidence of exploitation and land-use changes over time. There was a gradual decease in large terrestrial game in the area from 8000 BC to about 800 BC and then by 1050 AD (Early Medieval times/Viking times) these large terrestrial game and some large birds had disappeared. In the Middle Ages and time of Modernization (1050 AD – 1800 AD) there was a decline in fish such as salmon and the decline of birds and wetlands. During this time grey seals and large whales disappeared from the Wadden Sea. From 1800 to 1900 AD, “most birds, diadromous fish, large groundfish, oysters, and wetlands” declined and were often lost. As late as the 1970s, the system was still in decline and loss and was functionally transformed into a coastal mudflat and polluted sea with fish at very low levels.
Fishing and land-use changes, including building on wetlands and increased pollution from agriculture and industry had totally transformed the Wadden Sea. The authors state: “The loss of biodiversity, large predators, special habitats, filter and storage capacity, and degradation of water quality have led to a simplification and homogenization of the food web structure and ecosystem functioning…” Even 1000 years ago, humans at low population levels were transforming this ecosystem in ways that would lead to its simplification and homogeneity.
There is hope. We visited a national park and the staff talked about the measures being taken to protect the area. The Lotze et al paper also notes that since 1970 conservation measures have particularly resulted in the return of marine mammals and recovery of some bird species. Genesis 1 reminds us of God’s command not only to humans, but to the birds of the air and fish of the sea as well. We see in those few verses that God wants His ocean to flourish, which includes an abundance, diversity, and filling of the sea. The Wadden Sea is a lesson for us about how our actions can transform ecosystems and a warning about what one future might look like. It is a lot more work to restore something once it has been changed than to protect it in the first place. Also, I think this paper helps us to see how even low levels of exploitation by small groups of people can impact food webs and ultimately set the stage for ecosystem simplification.