Big Indiana Bass

Just received the most recent report on the Eel River initiative. The tagging program is still going through the first half of this year up there. Catch a tagged smallmouth and get BPS reward cards. Below is the Executive Summary from the report, but the full report is attached for download.

SUMMARY

A black bass survey was conducted on 46.4 miles (74.5 km) of the Eel River of north central Indiana from 24 June 2013 to 16 August 2013.

• Seven stations were sampled ranging in stream reach length from 3.6 miles (5.8 km) to 10.9 miles (17.5 km) with 21.5 hours of electrofishing.
• A total of 525 smallmouth bass (Micropterus dolomieu) (SMB) were captured and processed with a range in length of 3.2 to 13.3 inches (81-338 mm). Mean total CPUE fish/mile over all seven sample stations was 11.5 ±SE 2.
• All fish collected were age 1 to age 3 as aged by dorsal spines. Growth at each age class exceeded the Indiana and Eastern Cornbelt Plain average growth for SMB over the same age classes.
• Relative weights of all age classes represented in the Eel River survey was considered high at 101 for stock fish and 100 for quality fish.
• The PSD across all seven sample stations ranged from 4 to 36 with an overall PSD of 8.
• Of 110 fish aged by dorsal spines, 78 (71%) were 1+ with mean TL of 7.87 inches ±SE 0.17, 29 fish (26%) were 2+ with a mean TL of 10.76 inches ±SE 0.2 , and 3 fish (3%) were 3+ and mean TL of 12.53 inches ±SE 0.09.
• The mean QHEI across all 7 sample stations was 74 ±SE 0.86 (Good to Excellent Category).
• The year class strength of SMB is dependent on water quality spawning conditions in May and June. In 2012 during a drought year (June mean CFS 78), 27 SMB nests were documented while in 2013 (June CFS mean 1,440), no nests were documented.
• Over the seven sample stations, 200 rock bass (Ambloplites rupestris) were captured and processed. Rock bass ranged in size from 1.9 to 7.9 inches (48-201 mm). The CPUE per mile was 4.4.
• Six greater redhorse sucker (Moxostoma valenciennesi) were captured during the survey ranging in length 19.5 inches (495 mm) to 25 inches (635 mm).

Full report: download

• Download IDNR black bass final report 2014

By R. Ziert

In any environment the first priority of survival is food. In order to understand the source and thereby catch what eats that food, we first have to understand the niche makeup of the food chain web supply. What do Smallmouth Bass in the Great Lakes Chain of Lakes eat? What do any predators eat in any lake – what is most plentiful and when – which is easiest to catch? Invasive species will out sometimes, and unfortunately overcome other species; squeezing others to less prominence. But does the word “unfortunately” really have to apply over Adaptation?  Is adaptation the real key?  All living things adapt throughout their life cycles.

While this article centers on The Great Lakes of North America, it applies to any body of water and all species therein. Zooplankton being the primary source of food for fry of many species, that’s where we need to start. After growth from eating zooplankton, Gobies, Perch, Rainbow Smelt, Shad,  Salmon, Lake Trout, Pike, Large and Smallmouth Bass, and so on all eat each others fry, and young of the year’ sometimes they eat their own even after the “young of the year” stage. The most predominant species in numbers for the Great Lakes is the Rainbow Smelt – and therefore are the most likely to be eaten by other species most often.  So then, we need find out about their habits and move forward/up the food chain ladder.

Zooplanktons occur in one or more blooms throughout the year and in most lakes; more so in some than in others. Zooplankton eat phytoplankton. 

UWSP.EDU: “Each lake has a distinctive “personality,” or set of physical and chemical character which may change over time. Lakes or parts of lakes exhibit chemical changes on a daily basis while other changes, such as plant and algae growth, occur seasonally”. Plankton are born of Lake Bottom content and water column mix categorization; older lakes have more of this activity than younger ones. While the possibility of deeper water birth can exist, the type of Lake Bottom most likely to have plankton blooms are largely within the layer of water averaging from 5-20 feet deep. After the blooms, zooplankton, unlike vegetable/ algae/ phytoplankton, have some lateral movement ability but like all plankton, they are largely subject to water current/wind fetch for long range transport. All plankton being photo sensitive to light intensity, rise in the water column under overcast or darkened periods of day or night and sink during day under blue bird sky’s.

 “Gov.On.Ca”: “The rainbow smelt is a predatory fish native to the north Atlantic coastal regions of North America and a few lakes in the Ottawa Valley in the St. Lawrence River watershed. Deliberate stocking in Michigan in the early 1900s led to established rainbow smelt populations in lakes Erie, Michigan, Huron and Superior. The fish likely invaded Lake Ontario from Atlantic coastal areas through the Erie Canal. More recently people have illegally introduced rainbow smelt to inland lakes.

In their native habitat, rainbow smelt spend most of their lives at sea and migrate into fresh water to spawn. Rainbow smelt that have invaded Ontario waters cannot return to the sea, but they still follow old behavior patterns. In the spring they move in large schools from lakes into streams and along shorelines to spawn. Rainbow smelt eat plankton – small animals and plants found in the water – as well as the young of native fish species.

Range
Outside its native range, the rainbow smelt can be found in the St. Lawrence River watershed, the Great Lakes, other lakes such as Simcoe, Nipissing and Nipigon, and many smaller inland lakes. The fish has also been introduced to the Hudson Bay watershed, lakes in northwestern Ontario and Manitoba, including Lake Winnipeg, and many American states.

Impacts of Rainbow Smelt: By competing with other fish for food and eating the young of other species, rainbow smelt have had a serious impact on native species that eat plankton, as well as those that eat other fish.

• The rainbow smelt’s eating habits may disrupt food webs and lead to declines of the small animals known as zooplankton that are eaten by other fish. Zooplankton blooms and their flows after the spawn play an important part in finding fish that eat that resource and larger predators as well.
• The introduction of rainbow smelt has led to reduced populations of native fish species such as yellow perch (Perca flavescens), walleye (Sander vitreus), lake herring (Coregonus artedi), whitefish (C. clupeaformis) and lake trout (Salvelinus namaycush)”.
• Again, Rainbow Smelt eat plankton as fry and then eat the young of other species and may then be eaten by other adult fish,

 

What time of year do Rainbow Smelt Spawn and where specifically do they go to do so?

Many but not all Smelt die after they spawn.  Post Spawn and Acute Thermal Shock (which will be addressed later) account for the majority of smelt deaths. The beaches of the Great Lakes scattered with smelt bodies - stinking in the sun - will confirm such.

“Teaching Great Lakes Science”: “Spawning: Smelt spawn in tributaries over gravel beds at night and return to the lake by morning. Spawning is related to “spring thaw”, water temperature and warming spring rains and usually lasts about three weeks.

Spawn Habitat Water Temp: Cool, dark waters. Optimal water temperature is 43-56 degrees F.

When returning to deeper water of the watershed smelt prefer water temperatures of 61-70 degrees and do not often either go deeper than 20 feet nor one mile from shore. Accompanied by the need for food and thermocline formation, all normal or averages can be altered to fit specie needs.

Diet: All fry and small of the year prey including but not limited to - Opossum shrimp, a small shrimp-like crustacean, insects and insect larvae, other aquatic invertebrates, fish such as smaller smelt, emerald shiners, sculpins, juvenile burbot and whitefish and so on. Understanding the food chain web, overlaying and reasoning one niche with many others is vitally important to angling (catching fish); the who/which, what, why, where, and when.

Fishing strategy:  Relative to the smelt spawn, the best fishing for predators such as abundant Small Mouth Bass (don’t forget to look up their niche for come together purposes)  is in the main lake openings to tributaries and into tributaries or harbors proper at night between 10 p.m. – 2 a.m. during the spawning run. Smelt are not strong swimmers so look for the lesser of water flow. While some harbors may not have a natural water flow, boat traffic can generate same.

At times other than the spawn, look for the – as close to -  favored water column temperature range (deep water temperature probe needed) which will most likely not be affected by warmer water temperature swings causing the thermal shock mentioned earlier. Triangulate (there may be more than three sides to investigate) that estimate with known prey item habits/movements, and favorable basin strata. I.E. As an average look for 65 degree water at depth and add the other two features to the triangle. If that temperature specific is at 20 feet and a large storm moves through causing big 15 foot swells, the temperature range relative to depth will change from day to day. This same depth to temperature change will occur with the deepening thermocline as the season progresses. If any one part of the triangulation pulls the others sides in a specific direction as to temperature changes, the smelt will follow their food as much as they reasonably can. Of course, larger, heartier predator fish will pursue the smelt accordingly. Small Mouth Bass in particular may need basin relativity to associate them to their territory and niche. This detail will not hinder them from following their food source if need be.

One last tip would be that while alive and in water, Rainbow Smelt are said to give off a smell similar to cucumbers. Therefore, presenting baits at the periphery of  and slightly under smelt schools and using bait that looks and smells like a smelt can’t hurt your angling effort.

Where to get more information: Department of Natural Resources Fishing Report Hot Line (517) 373-0908. Or if you feel confident after the activity, test your science detective skills.

Z

 

Other Credits:

• Observant experience, authors education, and common sense. . . . and
• UWSP.EDU – understanding lake data.
• Ontario Canada - Government Specialties.
• Teaching Great Lakes Science – U.S. Gov. Services

For an expanded look at what’s going on here, refer to the following;

http://www.uvm.edu/seagrant/sites/u...

 

This video should get you a bit fired up - a big smallmouth sucking in a baitfish in slow motion. And there is an ulterior motive to this. Consider it the lead-in to the next post to come.