August 25, 2023
2023 Ecology Group Blog 2
Blog 2 of Ecology Group
Our blog is written to cover day3-day5. We moved from Pack Forest to Nature Bridge and were getting more moist along the way. Never-before-seen temperate rainforest ecosystems unfolded marvelously before our eyes. At the same time, the salmon conservation base also surprised us. So we will talk about what we have seen in the temperate forest and salmon protection.
Symbiotic Relationship
We went to Quinault Rain Forest in Olympic National Park (Photo 1). It is a wet condition due to high precipitation and meltwater from glaciers, and stores abundant nutrients. Therefore, the forest is habitat for many organisms. The environment is built on species helping each other. It called “symbiotic relationship”. Symbiotic relationship is one of essential element in Rainforest. Its definition is an association between different biological species. It is important for maintaining its biodiversity.
Photo 1. Quinault Rain Forest photo by Akira Kato
For example, moss has a symbiotic relationship with many plants. Many trees especially maple provides a habitat to moss, and in return, moss derive sustenance form air and water. The weight of moss on a large maple is estimated to be about 2t except water (Photo 2). If trees don’t have any moss, the rain forest cannot be in that site. Moss keeps water and prevents tree surface dry.
Photo 2. Trees wearing moss photo by Kazutaka Tabata
Another essential element is underground ecosystem. Plants absorb nitrogen from their roots through a lot of fungi. Fungi create a dense underground network (Figure 1), so underground organism network hold and spread much water and nutrition. Rainforest is not only what we can see but also underground ecosystem.
Figure 1. underground network: Marcel G. A. et. al 2009
A connection between aboveground and underground is trees and salmon. Salmon is one of the essential species for this forest. Approximately 80% of the nitrogen in this forest is provided by salmon. First, salmon is eaten by animals such as bears and wolfs, then dead salmon change into nitrogen. Underground organisms spread their nitrogen throughout the rainforest. That’s amazing!!
(This part written by kazutaka and nori)
Salmon Protection
We learned several things about salmon conservation on August 22 and 23. I will discuss them in this section. In the United States, Atlantic salmon once inhabited nearly every river west of the Hudson River.
Picture 1, Image of the Atlantic salmon.
This picture is from: https://www.fisheries.noaa.gov/species/atlantic-salmon-protected#spotlight
However, the population declined dramatically until the fishery closed in 1948. Why have Atlantic salmon populations declined? There are many reasons. The first and most important reason is the construction of dams. Dams create barriers to salmon migration and fragment their habitat. This makes it difficult for salmon to migrate between the ocean and rivers, making it difficult for them to reproduce. Gradually, salmon lost their genetic diversity.
There are other reasons. For example, the deterioration of the survival environment due to human pollution of rivers and oceans, and overfishing.
Various projects are currently underway to protect and restore Atlantic salmon. Examples include the removal of dams, releases, and bans on overfishing.
By the way, we went the Quinault National Fish Farm to learn about salmon conservation and aquaculture(photo 2).
Photo 2, He’s explaining the ecology of the salmon. August 21st, 2023.
Various efforts were made to protect the salmon. We will introduce the efforts of hatcheries to protect salmon ecology while farming salmon. Conservation of salmon is achieved through the sequence of fish spawning, rearing, marking and release. Raising salmon begins when the adult fish arrive at the hatchery. During autumn and winter, salmon that migrate from the Pacific into hatcheries remain in ponds until spawning. They classify fish based on species, maturity, and sex to ensure proper management. The female’s eggs are fertilized, washed, and then hatched. It grows into a baby fish known as “Alevin”. Alevins grow into juvenile fish “fry”. Fry are fed in large tanks.(Photo 3)
Photo 3 Tanks used for salmon farming. August 21st, 2023.
Adults are released directly into the Big Killsheen River in the spring. Adults are tagged as part of monitoring. Fin clip markings allow scientists and the public to identify hatchery and wild fish. Salmon travel five miles from the hatchery to the brackish mouth of the Hood Canal. This is the entire flow of salmon farming.
Salmon play a very important role in our diet and in maintaining ecosystem. Understanding their biology also helps us to protect them. I hope to continue to learn more about salmon and one day actually participate in their conservation.
(This part written by ryo and showskey)
Invasive Species
- preface
Invasive species are introduced species (also known as alien species) that not only reproduce excessively, but also cause damage to the environment they enter. Invasive species have negative impacts on habitats, bioregions, and cause ecological, environmental, and/or economic loss. The term can also refer to some native species when human activities alter food webs leading to their excessive proliferation and destruction – for example, along the northern California coast, the native sea otter was hunted to near extinction, allowing the native purple sea urchin to explode in number and devastate kelp forests. Since the 20th century, invasive species have become a serious threat to economies, societies, and environments.( Robert I., Hugh J.,2004)
Picture1: A beaver dam on Tierra del Fuego built by American beavers
From:https://zh.wikipedia.org/wiki/
The introduction of organisms into long-established ecosystems is a natural phenomenon, but introductions accelerated by human activities amplify the rate, scale, and geographic extent of invasions.Humans have acted as both accidental and intentional dispersal agents for thousands of years, beginning with early human migrations, accelerating during the Age of Discovery, and again with the onset of global trade.
- negative influence
Species invasion can lead to profound changes in the structure and function of the original ecosystem. Invasive species compete with native species for resources, and their excessive reproduction can directly reduce the number of native species, or even lead to species extinction, and indirectly reduce biodiversity. Invasive species can also cause genetic contamination through hybridization with native species, which in the long term may assimilate native species genotypes. In addition, invasive species can alter habitat types, which in turn affect other species that depend on that habitat. The introduction of multiple invasive species in a row creates complex interactions that sometimes promote the expansion of invasive species. Invasive plants can change the basic functions of ecosystem such as nutrient cycling and hydrology.
Picture2: Illustrative depiction of impact of invasive species on an ecosystem functioning.
From: September 2021, Environmental and Sustainability Indicators 12(3):100148
DOI:10.1016/j.indic.2021.100148
Some invasive animals such as forest pests can destroy trees on a large scale. Invasive species have a certain degree of uncertainty, the population may be small in the initial stage of invasion, after a period of time, rapid explosive growth, species invasion is one of the important causes of global biodiversity reduction, its ecological impact is usually far-reaching and extensive.
Picture3: impacts of invasive species and changes in biodiversity
From：Chapin et.al, 2000, Nature:405:234-242
Invasive species damage the biodiversity of the places they invade through different mechanisms. They can compete with native species for resources, resulting in a decline in native species. The genetic diversity of native species can also be reduced through hybridization. In addition, invasive species can alter habitat types and affect native species that depend on that habitat; Change the relationship of food chain and destroy the stability of ecosystem; Acting as a vector for pathogens, infecting native organisms. A large number of invasive plants can change vegetation types and reduce landscape diversity. Under the combined effect, the level of biodiversity in the invaded areas decreased significantly, the community composition converged, and the uniqueness was lost.
- How can invasive species be controlled
Picture4 :Warning signs to remind the public to recognize and report invasive species
Taken by group member 22th.Aug.2023
Controlling invasive species requires a variety of measures. One important and feasible method is to establish a monitoring network with public participation. Just as we saw during our hiking, warning signs can be set up in areas prone to invasive species, such as national parks and nature reserves, to remind the public to pay attention to the presence of invasive species, and report to relevant departments immediately once found. This can greatly improve the efficiency of monitoring invasive species. The public has more exposure to these areas in their daily lives and can play a good monitoring role. At the same time, this practice can also enhance public awareness of invasive species and improve prevention and control awareness. Countries and regions should give full play to the positive role of public participation and establish invasive species monitoring networks to better prevent and control invasive species.
(This part written by Zijun Wu and Xinru Zhang)
