Securely tie a second line, called a "trip line" to the crown of the Danforth anchor. This line needs to be longer then the anchor line and not coiled around the anchor line so it never has tension on it as the anchor line would. Many designs of this fluke-style anchor have a metal ring or hoop called a "trip ring" for ease of releasing the anchor from the lake or seabed. A short length of chain connected to the trip ring first will extend the life of the trip line.
If yours does not have this ring the trip line can also be lashed or tied securely to the anchor by using a figure-8 pattern around the stock ends for short term use because the tied end will be constantly buried everytime the anchor is used.
To ease the "dredging" of the lake bottom don't keep pulling anchor all at once. After you pull a few feet, try relaxing the line a little for a second before pulling again until you know you have cleared the bottom. The idea is to allow looser debris to fall away.
Each anchor's design is important to it's resistance to drag. Mushroom anchors are good for calm waters and muddy and sandy bottoms where it will sink into the sediment where suction holds it in place. Fluke anchors such as Danforths are good in heavy winds and current and for hard sand, grassy, and moderately rocky bottoms, but are less effective in clay where clumps can foul the flukes and prevent them from gripping well.
EDIT: Danforth's are prone however to become dislodged and not re-engage seabeds if the vessel pulls at the anchor perpendicular to the shank die to current or winds.
segments paraphrased from: https://www.westmarine.com/WestAdvisor/Selecting-The-Right-Anchor