Also go to the Natural Resources department and make an appointment to talk to a prof or advisor about their course work and what type of internships and employment students end up in. Are there any projects in the department you could get involved in? Anything locally?
Summer hiring will begin in a month or two. Work on your resume and reflect on how to present yourself in a cover letter. If you can get a Enviro Sci or Natural Resources prof to review and give suggestions that would be great. We found that career services really didn’t know how to frame a non generic letter.
Read through the job descriptions here and see if you would find them interesting.
https://limnology.wisc.edu/employment/summer-undergraduate-job-descriptions/
https://www.marinetech.org/internships/ Read through the summer intern blogs and concentrate on the ones doing scallop surveys. It is hard work but you will gain a lot of experience and exposure to a variety of jobs.
A year ago I put up this listing. http://talk.collegeconfidential.com/internships-careers-employment/1957208-natural-resources-environmental-science-internships-p1.html