Even within their department they have varying degrees of power., some as Peace Officers some not. I have no problem answering questions but I do have a problem with just anyone demanding I do so. Same with a search of my house, I have nothing to hide but that doesn't mean I'm open to anyone off the street knocking on the door and demanding I allow them to search my house.
Ziggy we are not talking anyone off the street here we are talking about somebody who has applied for a job, gone through an interview and training, and been hired by the minister to carry out specific duties. You might want to re think your hobbie if your worried DFO has as much or more power then RCMP!!
Here is the part about the minister appointing anyone he chooses to carry out some duties
"FISHERY OFFICERS AND FISHERY GUARDIANS
5. (1) The Minister may designate any persons or classes of persons as fishery officers or fishery guardians for the purposes of this Act and may limit in any manner the Minister considers appropriate the powers that a fishery officer or fishery guardian may exercise under this Act or any other Act of Parliament."
http://laws-lois.justice.gc.ca/eng/acts/F-14/page-4.html#h-6
Read more on that you'll see you have the right to ask them for their paperwork. If a creel survey person demands answers ask them for their certificate of designation if they don't have one your off the hook.
Here is the part on how much power a DFO officer has to inspect you.
http://laws-lois.justice.gc.ca/eng/acts/F-14/page-18.html#h-15
And here is the part we are talking about in this thread.
INFORMATION RETURNS
note : Persons who may be required to provide information
61. (1) The following persons may be required under this Act to provide information or to keep records, books of account or other documents:
(a) any person who engages in fishing;
(b) any person who purchases fish for the purpose of resale;
(c) any owner, operator or manager of an enterprise that catches, cultures, processes or transports fish; and
(d) any agent or employee of a person referred to in paragraphs (a) to (c).
note:Information that may be required
(2) A person referred to in subsection (1) may be required to provide information or to keep records or other documents relating to any of the following matters:
(a) the number, sex, size, weight, species, product form, value or other particulars of any fish caught, cultured, processed, transported, sold or purchased;
(b) the time and place at which any fish was caught or landed and the person, enterprise or vessel by which the fish was caught or landed;
(c) the time and place at which any fish was purchased and the person, enterprise or vessel from which the fish was purchased;
(d) the vessels, gear and methods used and the number of persons employed for the purpose of catching fish;
(e) the buildings, equipment, products and methods used and the number of persons employed for the purpose of culturing or processing fish; and
(f) any other matter relating to the proper management and control of fisheries or the conservation and protection of fish.
note : Duty to keep books
(3) A person referred to in subsection (1) shall keep any records, books of account or other documents that may be required by the regulations or by the terms and conditions of any lease or licence issued to the person under this Act and the records, books of account or other documents shall be kept in the manner and form and for the period prescribed by the regulations, lease or licence.
note : Duty to provide information
(4) A person referred to in subsection (1) shall, on the request of any fishery officer or fishery guardian, provide the officer or guardian, or any authority designated by the officer or guardian, with any information relating to a matter mentioned in subsection (2) that the officer or guardian may request.
http://laws-lois.justice.gc.ca/eng/acts/F-14/page-21.html#docCont
The Fisheries Act is a powerfull document. It's fun to read through too I learned a lot in just 20 minutes of browsing a few sections.