This week (22 July 2014-26 July 2014) I visited Dr. Michael Hammer, curator of fishes at the Museum and Art Gallery of the Northern Territory (Darwin, Northern Territory, Australia). The purpose of my visit was to subsample some of the Museum's clupeiform tissues. This was immensely helpful because I was able to obtain tissues from several species that I have not been able to collect myself and talk with Dr. Hammer about the sampling methods he uses to collect clupeiforms.
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After discussions with local researchers I decided to give up on cast netting and try seining for clupeiforms instead. As I have mentioned in previous posts, I have not been seining because crocodiles make it unsafe to wade in most coastal waters in northern Australia. However, I was told that as long as I am careful, I can get into the water in certain habitats that crocs don't frequent. Dr. Marcus Sheaves (James Cook University) helped me identify a local beach safe for seining as I was not confident that I could distinguish between safe vs. dangerous locations myself. We decided to try Rowes Bay Beach (right next to Townsville) a place where I have previously gone cast netting and not caught any clupeiforms. I had three volunteers (Christina Buelow, Anya Jaeckli, and Lea Stolpmann) help me seine. We were immediately successful, catching three species of clupeiforms, Hamilton's thryssa (Thryssa hamiltonii), white sardine (Escualosa thoracata), and broadhead anchovy (Stolephorus brachycephalus), on the first day! We collected four more times in Rowes Bay and caught many more anchovy specimens including two additional clupeiform species: Devis' anchovy (Encrasicholina devisi) and wolf herring (Chirocentrus dorab). Species cataloged in Bell Museum of Natural History: Family Engraulidae (anchovies): Thryssa hamiltonii, Stolephorus brachycephalus, Stolephorus nelsoni Family Clupeidae (herrings): Escualosa thoracata Family Sillaginidae (whitings): Sillago sp. Family Hemiraphidae (halfbeaks): Hyporamphus dussumieri Family Polynemidae (threadfins): Eleutheronema teradactylus Family Platycephalidae (flatheads): Platycephalidae sp. Family Callionymidae (dragonets): Callionymidae sp. Family Gobiidae (gobies): Gobiidae sp. Family Cynoglossidae (tonguefishes): Cynoglossidae sp. Collecting event details: Lat/long: -19.216522, 146.778134 Times: 07:30 to 09:30, 07:00 to 09:00, 08:30 to 11:00, 08:15 to 10:15, 15:30 to 17:30 Dates: 17 July 2014, 18 July 2014, 21 July 2014, 27 July 2014, 28 July 2014 As the title of this post suggests, I am not having much luck collecting clupeiforms. I have tried cast netting from docks, jetties, sandy beaches, and in the tidal Ross River Wetlands near Townsville, Australia. Previous studies (e.g. [1][2]) have documented clupeiformes in these locations during this time of year so I am not sure why I am not catching any. Interestingly, these studies used seines, gill nets, and trawls to catch clupeiformes rather than cast nets. I have been catching other species of fish, so I don't think my lack of success is a result of my cast-netting abilities. Consequently, I am starting to think that cast netting may not be the most effective way to catch my fish even though it is a good way to avoid getting eaten by a crocodile. On a more positive note, I have managed to collect some blennies (Family: Blenniidae) for fellow University of Minnesota Conservation Biology graduate student Peter Hundt. These fish were caught in tide pools on Magnetic Island (a 25 minute ferry ride from Townsville) with the help of James Cook University graduate students Michael Bradley and Christina Buelow. Species cataloged in Bell Museum of Natural History Family Labridae (wrasses): Halichoeres nigrescens (bubblefin wrasse), Novaculoides macrolepidotus (seagrass wrasse) Collecting event details: Lats/longs: (-19.250299, 146.822267), (-19.244222, 146.811067), (-19.24084, 146.798562), (-19.242222, 146.811067), (-19.240539, 146.791239), (-19.302669, 146.783996), (-19.300653, 146.790709), (-19.180562, 146.842595), (-19.129517, 146.876255) Times: 06 July 2014, 06 July 2014, 07 July 2014, 08 July 2014, 08 July 2014, 08 July 2014, 10 July 2014, 12 July 2014, 13 July 2014, Dates: 08:00-09:00, 20:00-21:00, 14:30-19:00, 07:45-09:10, 12:45-16:00, 17:30-19:00, 11:30-16:30, 15:00-17:30, 11:30-15:30 References [1] Hoedt (2002): Growth in eight species of tropical anchovy determined from primary otolith increments [2] Davis et al. (2012): Fish utilisation of wetland nurseries with complex hydrological connectivity I am now in Queensland Australia! During my stay in Australia I am staying in Townsville where I am being hosted by the Dr. Marcus Sheaves Lab at James Cook University. I have begun my collecting in Australia in mangrove creeks near Hinchinbrook Island, which is approximately a 1.5 hour drive north of Townsville. Doctoral students Michael Bradley and Ross Johnson in the Sheaves Lab are researching fish utilization of different habitat types in this area. Michael and Ross are accomplishing this by taking underwater videos using stationary cameras placed on the ocean floor. I joined Ross and Michael on some of their trips to Hinchinbrook because after placing the video cameras and before picking them up there was time for us to cast-net for clupeiformes. I have never tried cast netting before, but it was suggested to me that this would be a good method to catch clupeiformes in Australia because the crocodiles make it very dangerous to wade in the water. Cast-netting from the boat I was able to collect many individuals of a single species of herring, Herklotsichthys castelnaui. In the evenings I also tried cast netting off of some docks as well as a jetty in Lucinda, Queensland near our hotel. Again, I mainly caught H. castelnaui, but one evening I also caught two Stolephorus brachycephalus and one Thryssa setirostris. I puzzled why I have been unable to catch very many species of clupeiforms because the habitats I have been fishing in certainly seem good for them. I will try cast netting in different habitats and at different times of day and hopefully I will have more luck catching different species. Collecting event details: Lat/long: 18* 26' 43.69" S, 146* 09' 11.54" E Dates: 04/June/2014, 09/July/2014, 19/July/2014 Video: Coming soon! During my final week in Taiwan I went to Penghu Island with Zhao Yu Shen, Peter Hundt, and Tsai Wen Yu to collect clupeiformes for my research and blennies for Peter's research. We visited some commercial fishermen who regularly catch clupeiformes. The fishermen were very kind and gave me some Sardinella lemuru and Spratelloides gracilis samples. Peter then taught Yu Shen, Wen Yu, and I how to catch blennies. We spent two days snorkeling for blennies, which was a lot of fun, and we were able to catch several species (full list of species will be added asap!). Collecting event details: Lat/long: 23.666672, 119.603375 (sardine & sprat gifts), 23.651046, 119.517561 (blenny collecting) Dates: 19/June/2014 - 21/June/2014 Our most northerly collecting location in Taiwan this year was at a muddy/sandy beach at the mouth of the Chonggang River near a town called Houlong, in Miaoli County. I collected with Meng Cheng, Zhao Yu Shen, Tsai Wen Yu, and Peter Hundt. The water temperature at this site is generally cooler than our other sampling locations and we typically catch different clupeiform species. We had really good luck at this location this year. We caught a large number of individuals from several clupeiform species (Nematalosa come, Thryssa chefuensis, and Engraulis japonicus), which will allow me to conduct a thorough investigation of their diets. We also several other species of fishes as well as plant and invertebrate samples for stable isotope analysis. Stay tuned because I will add a complete list of these taxa soon as I am back in the United States and have access to my specimens again. Collecting event details: Lat/long: 23.137349 N, 120.113435 E & 23.142513 N, 120.072062 E Time: 15:00 - 17:00 & 15:30 - 17:30 Dates: 30/May/2014 & 12/June/2014 Video: Fieldwork 2014 Episode Five - Qigu (七股區), Houlong (後龍鎮), and Haomeili (好美里 Vincent Chen and I tried collecting a second time at Shuang Chun. This time we went at night in an attempt to catch different clupeiform species. It was very windy and difficult to seine and unfortunately we caught no clupeiformes. However, we did catch some shrimp scad (Alepes djedaba), mullet (Family: Mugilidae), and a really strange looking goby (Family: Gobiidae). Collecting event details: Lat/long: 23.305965 N, 120.108181 E Time: 19:00 - 22:30 Date: 09/June/2014 Video: Fieldwork 2014 Episode Four - Shuang Chun (雙春) On the 29th and 30th of May I had the pleasure of collecting with Yu Shen (National Chiayi University (NYCU)), Cris Fann (NCYU), Li An (NCYU), Kuo Meng Lin (NCYU), and Peter Hundt (University of Minnesota). We collected fish in a small muddy bay bordered by mangroves. Unlike my previous visits to Haomeili this year, the tide was high enough to fish without having to trudge walk around in the deep mud that is further out into the bay (see the mud in Haomeili Day 2 crab video). We caught a lot of fish! Although I have not actually counted yet, I think that we collected more fish on these two days than on any other days this year. Importantly, we caught several species of clupeiforms including Thryssa hamiltonii, Encrasicholina heteroloba, Nematalosa come, and an unknown species of sardine. I will update this post with a list of the species we caught with pictures of the specimens as soon as possible. Collecting event details: Lat/long: 23.360286, 120.129894 Time: 15:30-18:00 Date: 29/May/2014 & 30/May/2014 Video: Fieldwork 2014 Episode Five - Qigu (七股區), Houlong (後龍鎮), and Haomeili (好美里 Today Dr. Kuo took Chao Hung, Xiu Yi (all from National Chiayi University) and I to Qigu (七股區), Taiwan County, to visit his friend Mr. Shen who is a fisherman and oyster farmer. Mr. Shen graciously offered to help us collect some fish. While waiting to go fishing we watched freshly harvested oysters being unloaded from small fishing boats. This presented us with an unexpected opportunity to collect blennies (Family: Blenniidae), a goby (Family: Gobiidae), algae, and invertebrates that were hiding amongst the oysters when they were loaded onto the boats. Mr. Shen then took us to a small bay bordered by a small island on his fishing boat. In this bay there were a lot of oyster farming platforms as well as "fish corrals," which are used to guide fish into hoop traps. From Mr. Shen's traps we were able to collect Nematalosa come (Family: Clupeiformes), Leiognathids (Family: Leiognathidae), sparids (Family: Sparidae), and some Pomadasys quadrilineatus (Family: Haemulidae). Collecting event details: Lat/long: 23.137349 N, 120.113435 E & 23.142513 N, 120.072062 E Time: 15:00 - 19:00 Date: 04/June/2014 Video: Fieldwork 2014 Episode Five - Qigu (七股區), Houlong (後龍鎮), and Haomeili (好美里) Today we tried collecting fish at a new location, just south of Haomeili, called Shuang Chun. I was assisted by three undergraduate students from National Chiayi University: Cris Fann, Chao Hung, and Vincent Chen. The beach at this location was large and sandy with some wetlands and a river inflow nearby. Therefore, I thought this would be a good spot to collect my fish. However, the only clupeiforms we captured were two small Thryssa setirostris. Additionally, we caught a few Alepes djedaba (Family: Carangidae), 2 species of leiognathids (Family: Leiognathidae), a lot of jelly fish, and some moon crabs (Matuta victor). See my YouTube Video for more! Collecting event details: Lat/long: 23.308193 N, 120.109362 E Time: 08:30 - 10:30 Date: 07/June/2014 Video: Fieldwork 2014 Episode Four - Shuang Chun (雙春) |
AuthorJosh Egan is a graduate student in the University of Minnesota's Conservation Biology Graduate Program. Archives
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