August 3rd, 2015 – Fish Seining and Identification / Biology of Wetlands / Aquatic Reptiles
Blog entry written by: White Winged Scoter (Melanitta deglandi)
Team Members: Manreet Kaler (Western), Chang Liu (Tongji), Mengxi Wu (SWU), Anyi Tang (Fudan)
Weather: Windy, cloudy and some precipitation, Temperature: 17-27° C
This morning, we started by learning the fundamentals of fish seining. We had the pleasure of having two very experienced fish seiners, Changhai Zhu and Professor Madison in addition to Professor Wong to lead this practicum. We started off by taking out the fish seining net and learning about its uses. The top part of the net is called the floater and the bottom part of the net has weights on it. This type of net is only good for fish seining along shorelines and not for deep water as it is not wide enough. It is very important to select your area very carefully, which is one of the steps in being a good biologist. Another imitation to using this method, is that other species such as turtles could get stuck into the net and hence suffocate causing them to eventually die. This can be prevented by having constant observation. In addition, fish seining is not the only way to catch and identify fish, as you can also set traps with bait, or set up gill nets to catch a school of fish.
The class was divided into two large groups of about 16 people each. While the first group was fish seining, the second group, which we were a part of, was working on the wetland assessments. After the first group came back, we were taken by van to a part of Lake Opinicon, within Queens biological station, which was only about a two minute drive (18T E394486 N4935626). The first part in this fish seining and identification practicum was to put the net into the water, with one person on each side to spread it out. This was followed by the use of two volunteers who helped with putting the net in the proper position to allow fish to be caught within. Once the net was spread accurately, Professor Wong and some of the other students were able to round it up to keep the fish from escaping the pocket underneath, which is built in the middle of the net. Once the fish were securely in the net, we took them out and transferred them into buckets.
The reason for putting all the fish that were collected by the net into three different buckets was to help count and identify them individually. The three buckets were brought out of the water, and using the “Peterson Field Guides: Freshwater Fishes” we were able to successfully learn and classify the fish accordingly. As we would take one fish out of the bucket, with help of all the professors, we would state the fish species and then put it into a larger bucket. We also had to make sure to count how many of each species of fish we had collected in order to get a better understanding of the types of fish that reside by slow moving shorelines.
All together, we collected 158 fishes, of 7 different species, including Pumpkinseed (Lepomis gibbosus), Bluegill (Lepomis macrochirus), Yellow Perch (Perca flavescens), Largemouth Bass (Micropterus salmoides), Banded Killifish (Fundulus disphanous), Bluegill Pumpskinseed Hybrid, and Juvenile Chub (Hybopsis). The data collection is shown below.
Table 1. The number of fish collected according to their specific species.
|Fish Species||Number Collected|
|Pumpkinseed (Lepomis gibbosus)||38|
|Bluegill (Lepomis macrochirus)||90|
|Yellow Perch (Perca flavescens)||20|
|Largemouth Bass (Micropterus salmoides)||6|
|Banded Killifish (Fundulus disphanous)||1|
|Bluegill Pumpskinseed Hybrid||2|
|Juvenile Chub (Hybopsis)||1|
Each species of fish were identified based on different characteristics including, size, gill, dorsal fin, scales, colour, etc. The Pumpkinseed, a type of sunfish can be identified as having one dorsal fin, with many bold dark brown lines and orange spots. It also has bright red and orange spots with a light coloured edge on the black earflap. Pumpkinseeds are found by the shoreline, as they are tolerant to hypoxia. They have a small mouth and many gold and yellow flecks. Bluegills which were the most common fish found in our sample, are not as tolerant to hypoxia as Pumpkinseeds but are also a type of sunfish. It can sometimes be hard to identify between a Bluegill and a Pumpkinseed. Bluegills have large black spot at the rear of the dorsal fin. They have a long pointed pectoral fin which extends past their eye. They also have a small mouth, as their upper jaw does not extend under eye pupil. They have blue streaks from the chin to the edge of the gill cover, and are white to yellow below.
We also found a couple fishes of other species that were not as common. The Yellow Perch for example has a fairly deep compressed body. It is green above and has some yellow on the side. It also has a larger mouth than some of the other fish and yellow paired fins. Furthermore, the Largemouth Bass has a very large mouth in comparison to everything else that was caught today. It is silver and brassy green above with a dark olive mottling. Another type of fish that we identified was the Banded Killifish, which are found to be pretty rare around this area, have long slender bodies, with green and brown bars along the silver side. They also have a brown stripe along the back. The hybrid that was caught is a hybrid between the Pumpkinseed and the Bluegill. These are actually fairly frequent in aquatic shoreline habitats. The final type of fish that was caught was the Juvenile Chub. There are many different Chub species, and it can be hard to identify Juvenile Chubs since they are very small and not fully developed.
Once we identified and recorded all the fish species that were collected, we placed them all back into the lake. It is important to be efficient since you do not want to keep the fish out of their habitat for a large amount of time, as it can eventually be detrimental. We noticed that it was irritating for some of the larger fish to be constrained to a bucket, as it was a small amount of space. As a good biologist it is important to know the different fish species well so that when you are identifying, you can do it accurately but also at a fast pace. Once we placed all the fish back into the lake, we made our way back to the main lodge of Queens Biological Station by foot.
After having a delicious meal at lunch, we continued the day with two exciting lectures lead by Professor Wong and Professor Lougheed in the seminar room. The first lecture was on the biology of wetlands. Professor Wong explained the definition of wetlands and how to classify them. Wetlands are an area permanently or recurrently inundated or saturation at the near surface by surface water or ground water. Wetlands have certain characteristics such as, soils are water saturated, vegetation is dominated by large and unique plant species, and they share features with the aquatic and terrestrial ecosystems as well. There are two main things that make the wetlands unique: 1. Anaerobic soils, which are saturated soils that are quickly depleted by microorganisms and 2. Macrophytes, which are large plants such as ferns, shrubs, trees and grass. It is very crucial to understand the importance of the wetlands, in order to sustain local and regional biodiversity. There are many different wetlands, such as bogs, swamps, ferns, shallow water, and marshes. Within these wetlands they will have different landforms as well as different climates. The wetlands hydrology will also play a role in the kind of vegetation that will grow.
The final lecture given by Professor Lougheed on aquatic reptiles explained the different reptile species that we may find around the world as well as around Ontario. He also provided the class with an understanding of the importance of different reptile species, such as turtles, crocodiles and lizards and their endangerment concerns. These species are keystone species meaning that they are very important, as other species are very dependent on them. Some characteristics of reptiles include: they are ectothermic, mostly lay amniotic eggs, some have pits for infrared sensing and all breathe through their lung but some have permeable skin and respire through their cloaca. Some examples of reptiles include: Leather back sea turtle (Dermochelys coriacea), Eastern long-necked turtle (Chelodina longicollis), Saltwater crocodile (Crocodylus porosus), Northern water snake (Nerodia sipdon) and Marine iguana (Amblyrhynchus cristatus). There is an extinction crisis among reptiles. There has been a 50% decline, recorded from the global living planet index from 1970-today. Reptiles serve importance not only to their ecosystems but also to us. Snakes for example, can serve as predators for some pests. In some cultures they are used for food and leather. Snake venom recently is being used for medicine purposes as well. Therefore by understanding reptiles we can then try to help in playing a role to conserve them.
We ended the day off after dinner by working on our wetland assessments. Today was filled with many amazing learning opportunities and also lots of fun working in the field.
|驼背太阳鱼 (Lepomis gibbosus)||38|
|蓝鳃太阳鱼 (Lepomis macrochirus)||90|
|大嘴黑鲈 (Micropterus salmoides)||6|
|秀体底鲢 (Fundulus disphanous)||1|
第二个演讲是Lougheed教授讲述的在世界各地的以及安大略省的不同水生爬行类动物。他同样也讲到了不同类型爬行类动物的重要性，例如乌龟、鳄鱼、蜥蜴以及其他一些濒临灭绝的动物。这些动物是基本的物种，它们十分重要，其他物种的存在也取决与它们。一些爬行类动物的特征包括：有关爬行动物的一些特征包括：他们是变温动物，产羊膜卵，有些种类有颊窝可以用于红外感知。几乎所有种类都利用肺呼吸，不过有一些种类具有透气皮肤并可通过泄殖腔呼吸。爬行动物的一些代表包括：棱皮龟（Dermochelys coriacea），东方长颈恐龟（Chelodina longicollis），咸水鳄（Crocodylus porosus），北方水蛇（Nerodia sipdon）和海鬃蜥（Amblyrhynchus cristatus）事实上，爬行动物也面临着种族灭绝的危机。据生命行星指数统计，自1970年至今爬行动物已减少大约50%。